Connexin32: a mediator of acetaminophen-induced liver injury?

Connexin32 is the building block of hepatocellular gap junctions, which control direct intercellular communication and thereby act as goalkeepers of liver homeostasis. This study was set up to investigate whether connexin32 is involved in hepatotoxicity induced by the analgesic and antipyretic drug acetaminophen. To this end, whole body connexin32 knock-out mice were overdosed with acetaminophen followed by sampling at different time points within a 24-h time frame. Evaluation was done based upon a series of clinically and mechanistically relevant read-outs, including protein adduct formation, histopathological examination, measurement of alanine aminotransferase activity, cytokine production, levels of reduced and oxidized glutathione and hepatic protein amounts of proliferating cell nuclear antigen. In essence, it was found that genetic ablation of connexin32 has no influence on several key events in acetaminophen-induced hepatotoxicity, including cell death, inflammation or oxidative stress, yet it does affect production of protein adducts as well as proliferating cell nuclear antigen steady-state protein levels. This outcome is not in line with previous studies, which are contradicting on their own, as both amplification and alleviation of this toxicological process by connexin32 have been described. This could question the suitability of the currently available models and tools to investigate the role of connexin32 in acetaminophen-triggered hepatotoxicity.     

Erythropoietin regulates apoptosis, inflammation and tissue remodelling via caspase-3 and IL-1β in isolated hemoperfused kidneys

Ischemia reperfusion injury associated with apoptosis and inflammation plays crucial roles in renal transplantation. Erythropoietin provides renoprotection, but its effects and mechanisms on kidney preservation are not fully defined. Porcine kidneys, subjected to 10 min warm ischemia, underwent 16 h cold storage followed by 2 h normothermic hemoperfusion with or without 5000 units/L erythropoietin. Apoptotic cells were increased in tubular lumens and interstitial areas by normothermic perfusion alone, but decreased in tubular areas by additional erythropoietin. Myeloperoxidase+ cells, free cells and cell debris in tubular lumens were gradually increased by cold storage, normothermic perfusion and erythropoietin in normothermic perfusion. Accordingly, caspase-3 activity as well as its active proteins was increased by normothermic perfusion and furthered by erythropoietin. In contrast, macrophage L1 protein positive cells in tubulointerstitial areas, cytokine interleukin (IL)-1β activation, tubular dilation and vacuolation were raised by normothermic perfusion, but all alleviated by erythropoietin, with higher urine output. The migration of myeloperoxidase+ cells with apoptotic features and apoptotic cells with polymorphous nuclei from tubulointerstitial areas into tubular lumens was widely displayed in the kidneys, especially those preserved by erythropoietin in normothermic perfusion. HSP70 protein was enhanced by normothermic perfusion regardless of erythropoietin. In addition, erythropoietin induced a dose-dependent increase in caspase-3 precursor in porcine proximal tubular cells (LLC-PK1) and also stimulated caspase-3 cleavage in cisplatin-treated cells. In conclusion, erythropoietin promotes inflammatory cell apoptosis, drives inflammatory and apoptotic cells into tubular lumens, eventually leads to inflammation clearance, renoprotection and tissue remodelling through caspase-3 and IL-1β in isolated haemoperfused kidneys.     

Role of TGF-β in melanoma

Human malignant melanoma is highly resistant to chemotherapy and current immunotherapeutic approaches induce long term remission only in the minority of patients. The transforming growth factor-β (TGF-β) has attracted much attention as a therapeutic target because it plays an important and pleiotropic role in melanoma progression. TGF-β is a multifunctional cytokine involved in the regulation of many cellular processes including cell proliferation, differentiation and survival. Resistance to the growth inhibitory effects of TGF-β without alterations of TGF-β signaling molecules is characteristic of cutaneous melanoma. Melanoma produces increasing amounts of TGF-β with disease progression, inhibiting immune responses and providing an optimal microenvironment for undisturbed tumor growth. In addition, TGF-β exerts its tumor promoting functions via direct effects on tumor cell motility and invasiveness and indirectly by modulating tumor stroma and extracellular matrix, supporting angiogenesis and inhibiting immune surveillance. TGF-β acts through multiple intracellular signaling pathways and the outcome of TGF-β signaling is context-dependent. Defining the impact of the different TGF-β signaling pathways on melanoma progression will help to identify suitable therapeutic targets. Here we review the current knowledge of TGF-β in melanoma and discuss recent therapeutic approaches targeting the TGF-β pathway.     

Cooperative role of tumour necrosis factor-α, interleukin-1β and neutrophils in a novel behavioural model that concomitantly demonstrates articular inflammation and hypernociception in mice

BACKGROUND AND PURPOSE

Chronic joint inflammation and pain are the hallmarks of disease in patients with inflammatory arthritis, notably rheumatoid arthritis. The aim of the present study was to investigate the relative contribution of tumour necrosis factor (TNF)-α, interleukin (IL)-1β and neutrophil influx for joint inflammation and nociception in a novel murine model of antigen-induced arthritis (AIA).

EXPERIMENTAL APPROACH

AIA was induced by administration of antigen into knee joint of previously immunized mice. Neutrophil accumulation was determined by counting neutrophils in the joints and assessing myeloperoxidase activity in tissues surrounding the joints. TNF-α, IL-1β and CXCL-1 were measured by elisa. Mechanical hypernociception was assessed in parallel, using an electronic pressure meter.

KEY RESULTS

Hypernociception was dependent on antigen dose and the time after its administration; it was prevented by treatment with morphine and associated with neutrophil infiltration and local production of TNF-α, IL-1β and CXCL-1. Administration of a chimeric monoclonal antibody to TNF-α (infliximab) or IL-1receptor antagonist prevented neutrophil influx and hypernociception, and this was comparable to the effects of dexamethasone. Treatment with fucoidin (a leucocyte adhesion inhibitor) greatly suppressed neutrophil influx and local production of TNF-α and IL-1β, and hypernociception.

CONCLUSIONS AND IMPLICATIONS

In conclusion, the present study describes a new model that allows for the concomitant evaluation of articular hypernociception and inflammation. Using this system, we demonstrated that a positive feedback loop involving neutrophil influx and the pro-inflammatory cytokines TNF-α and IL-1β is necessary for articular hypernociception after antigen challenge of immunized mice.     

Advance in study of interleukin-1 family cytokines in liver diseases北大核心CSCD

Liver disease is a serious threat to human health in the world, including hepatitis caused by various causes (fatty, alcoholic , viral and autoimmune hepatitis) , liver fibrosis and liver cancer. Interleukin-1 (IL-1) family members are involved in the inflammation of most acute and chronic liver diseases and play a key role in the progression of liver diseases. This paper reviews the research progress on the relationship between interleukin-1 family cytokines and liver diseases,discusses the key roles of IL-1 family cytokines in the occurrence and development of various liver diseases and related immune responses, and looks forward to the application prospect of IL-1 family members in drug devel¬opment and clinical treatment. © 2023 Publication Centre of Anhui Medical University. All rights reserved.     

Synergistic effects of interleukin-1β and interleukin-17A antibodies on collagen-induced arthritis mouse model

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease that mainly causes the synovial joint inflammation and cartilage destruction. Both interleukin-1β (IL-1β) and Interleukin-17 (IL-17) are important proinflammatory cytokines involved in the pathogenesis of RA. We investigated whether combination therapy with IL-1β and IL-17A antibodies would generate the potential for synergistic effects on a collagen-induced arthritis (CIA) mouse model. Mice with CIA were subcutaneously injected with humanized IL-1β antibody, IL-17A antibody, or combination treatment. The effects of treatment were determined by arthritis severity score, histological damage and bone destruction, autoreactive humoral and cellular immune responses and cytokine production. Treatment with IL-1β antibody or IL-17A antibody alone resulted in beneficial effects on clinical and histological parameters of CIA mice. Compared with the single antibody treatments, the combination therapy resulted in a more significant effect in alleviating the severity of arthritis by preventing bone damage and cartilage destruction, reducing humoral and cellular immune responses, and down-regulating the expression of IL-1β, IL-6, IL-17A, IFN-γ, RANKL and MMP-3 in inflammatory tissue. In conclusion, combination treatment with humanized IL-1β and IL-17A antibodies demonstrates synergistic beneficial effects for preventing joint inflammation and cartilage destruction and bone damage in CIA mice model. These studies also provide evidence that combination with IL-1β and IL-17A antibodies may lead to a new combinatorial therapy for RA patients.     

Role of tumor necrosis factor and nitric oxide in the protection of N-methyl-N-(3,4-methylenedioxybenzoyl) methyl-acetamide against immunological liver injury in mice

研究了Ｎ－甲基－Ｎ－（３，４－亚甲二氧基苯甲酰）甲基－乙酰胺（ＳＹ－６４０）的保肝作用及其机理．给小鼠ｉｖ活卡介苗（ＢＣＧ）１２ｄ后再ｉｖ脂多糖（ＬＰＳ）诱导小鼠血浆一氧化氮（ＮＯ），肿瘤坏死因子（ＴＮＦ），谷丙转氨酶（ＧＰＴ），谷草转氨酶（ＧＯＴ）剧烈升高及严重的肝损伤．以ＳＹ－６４０给小鼠ｉｇ（每日一次，连续１０ｄ），显著降低ＢＣＧ＋ＬＰＳ诱导的肝损伤小鼠血浆ＧＰＴ，ＧＯＴ和ＴＮＦ水平的升高，血浆ＮＯ水平的升高更加显著，肝损伤减轻．以单甲基精氨酸抑制ＮＯ的生成，ＳＹ－６４０的上述作用被抵消．ＳＹ－６４０对正常小鼠血浆ＮＯ，ＧＰＴ，ＧＯＴ水平无影响．可见，ＳＹ－６４０的保肝作用与其升高血浆ＮＯ，降低血浆ＴＮＦ水平有关．     

Influences of Kupffer cell stimulation and suppression on immunological liver injury in mice

研究库普弗细胞（ＫＣ）是否参与小鼠免疫性肝损伤．方法：给小鼠静脉注射卡介苗（ＢＣＧ）５×１０７活菌后再静脉注射脂多糖（ＬＰＳ）７５μｇ以诱导免疫性肝损伤．以维生素Ａ激活ＫＣ和以印度墨汁或硅砂封闭ＫＣ后，测定血浆一氧化氮（ＮＯ），谷丙转氨酶（ＡｌａＡＴ），谷草转氨酶（ＡｓｐＡＴ）的变化并检查肝组织的病理改变．结果：注射ＢＣＧ后，再注射ＬＰＳ７５μｇ，可导致小鼠血浆ＮＯ，ＡｌａＡＴ，ＡｓｐＡＴ剧烈升高及严重的肝损伤．以维生素Ａ激活ＫＣ后，肝损伤更为严重，而以印度墨汁或硅砂封闭ＫＣ后，肝损伤则显著减轻．结论：ＢＣＧ＋ＬＰＳ诱导的小鼠肝损伤与ＫＣ的功能关系密切，来源于ＫＣ的ＮＯ在ＢＣＧ＋ＬＰＳ诱导的肝损伤中起重要作用．     

Metadoxine inhibits the infiltration of macrophages and neutrophils into liver tissue in acute alcoholic liver injury

Alcohol consumption causes significant liver damage, including hepatitis, fibrosis, cirrhosis, and even primary liver carcinoma. Metadoxine (MTDX) is considered to be a beneficial treatment for alcoholic liver disease (ALD) because it accelerates the metabolism and elimination of ethanol. However, the underlying mechanism is not well understood. Here, the rat model of ALD was developed by feeding with 50% ethanol at the dose of 5 g/kg, and samples of serum and liver tissue were collected to test the levels of liver injury and inflammation and evaluate the hepatoprotective function of MTDX in alcohol-induced liver injury. Further investigation on the infiltration of immune cells was performed to understand the potential hepatoprotective mechanism of MTDX in the ALD model. The results showed that MTDX attenuated liver injury, evidenced by decreased levels of alanine transaminase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP). Meanwhile, the liver proinflammatory environment was improved after MTDX treatment, evidenced by decreased levels of TNF-α, IL-6, and NLRP3 in the liver tissue. Furthermore, inhibited infiltrations of macrophages and neutrophils were observed in MTDX-treated ALD rats compared with the untreated ALD rats. Our results indicated that MTDX played an important role in preventing the progression of ALD, and the underlying mechanisms might be related to its function of attenuating liver inflammation by inhibiting immune cell infiltration.     

Tacrolimus ameliorates dextran sulfate sodium-induced colitis in mice: implication of interferon-γ and interleukin-1β suppression

We investigated the effect of tacrolimus, a calcineurin inhibitor, on dextran sulfate sodium (DSS)-induced colitis. After inducing colitis in C57BL/6 mice by administering DSS solution as drinking water for 7 d, the animals were treated with tacrolimus. Severity of colonic inflammation was evaluated based on colon weight per unit length. Levels of cytokines (interferon (IFN)-γ, interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-12, and tumor necrosis factor (TNF)-α) released from isolated inflamed colons of mice treated with tacrolimus or vehicle were also measured. Treatment with tacrolimus for 14 d reduced the colon weight per unit length and suppressed the release of IFN-γ and IL-1β, but not other cytokines, in inflamed colons of colitic mice compared with vehicle-treated mice. A positive correlation was noted between colon weight per unit length and released level of IFN-γ or IL-1β. The release of IFN-γ and IL-1β was also suppressed after single dosing with tacrolimus to colitic mice. Taken together, these results suggested that tacrolimus ameliorated DSS-induced colitis by suppressing release of IFN-γ and IL-1β from inflamed colon.     

Phytoglycoprotein inhibits interleukin-1β and interleukin-6 via p38 mitogen-activated protein kinase in lipopolysaccharide-stimulated RAW 264.7 cells

This study was carried out to investigate the anti-inflammatory effects of 30-kDa glycoprotein isolated from Dioscorea batatas Decne (DBD glycoprotein), which consists of carbohydrate content (61%) and protein content (39%) on lipopolysaccharide (LPS, 2 μg/ml)-stimulated RAW 264.7 cells. We found that DBD glycoprotein (200 μg/ml) has an inhibitory effect on the production of intracellular hydrogen peroxide (H₂O₂), on the phosphorylation of p38 mitogen-activated protein (MAP) kinase, on the DNA binding activity of activator protein-1 (AP-1), and on c-Jun and c-Fos protein expression, respectively. In addition, DBD glycoprotein treatment markedly suppressed the interleukin (IL)-1β, IL-6, and inducible nitric oxide synthase (iNOS) expression and the production of nitric oxide (NO) in LPS-stimulated RAW 264.7 cells. Interestingly, IL-1β, IL-6, and iNOS expression was significantly attenuated by treatment with protein kinase C (PKC) inhibitor (staurosporine) as well as p38 MAP kinase inhibitor (SKF86002) in LPS-stimulated RAW 264.7 cells. On the basis of these results, we assume that DBD glycoprotein has anti-inflammatory potential, which can modulate proinflammatory signal transduction in LPS-stimulated RAW 264.7 cells.     

Role of PKC-β in chemical allergen-induced CD86 expression and IL-8 release in THP-1 cells

We previously demonstrated an age-related decrease in receptor for activated C-kinase (RACK-1) expression and functional deficit in Langerhans cells’ responsiveness. This defect specifically involves the translocation of protein kinase C (PKC)-β. The purpose of this study was to investigate the role of RACK-1 and PKC-β in chemical allergen-induced CD86 expression and IL-8 release in the human promyelocytic cell line THP-1 and primary human dendritic cells (DC). Dinitrochlorobenzene, p-phenylenediamine and diethyl maleate were used as contact allergens. The selective cell-permeable inhibitor of PKC-β and the broad PKC inhibitor GF109203X completely prevented chemical allergen- or lipopolysaccharide (LPS)-induced CD86 expression and significantly modulated IL-8 release (50 % reduction). The selective cell-permeable inhibitor of PKC-ε (also known to bind to RACK-1) failed to modulate allergen- or LPS-induced CD86 expression or allergen-induced IL-8 release, while modulating LPS-induced IL-8 release. The use of a RACK-1 pseudosubstrate, which directly activates PKC-β, resulted in dose-related increase in CD86 expression and IL-8 release. Similar results were obtained with human DC, confirming the relevance of results obtained in THP-1 cells. Overall, our findings demonstrate the role of PKC-β and RACK-1 in allergen-induced CD86 expression and IL-8 production, supporting a central role of PKC-β in the initiation of chemical allergen-induced DC activation.     

Dihydropyranoaurone compound damaurone D inhibits LPS-induced inflammation and liver injury by inhibiting NF-κB and MAPK signaling independent of AMPK

Recently, we reported the synthesis of damaurone D (DD), originally derived from Rosa damascene, and its anti-inflammatory effect in macrophages. Here, we investigated the molecular mechanism underlying the anti-inflammatory effect of DD in macrophages and further tested whether DD is protective against lipopolysaccharide (LPS)-induced liver injury. DD inhibited LPS-stimulated expression of pro-inflammatory genes and cytokine/chemokine secretion in a concentration-dependent manner in RAW 264.7 cells and thioglycolate-elicited mouse peritoneal macrophages. DD suppressed LPS-stimulated nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, as demonstrated by reduction in IκB kinase α/β phosphorylation, IκBα degradation, and levels of phosphorylated ERK, JNK, and p38 MAPK. The luciferase reporter activity of NF-κB and activator protein 1 was also attenuated by DD pretreatment. Furthermore, DD treatment induced AMP-activated protein kinase (AMPK) activation in cells and mouse liver, although the anti-inflammatory effect of DD was similar in dominant-negative AMPK-overexpressing cells. Lastly, DD-treated mice were protected against LPS-induced acute liver injury, based on morphologic and immunohistochemical observations; reduction in the plasma levels of aspartate aminotransferase, TNF-α, and MCP-1; and a decrease in inflammatory gene expression. In summary, our findings indicate that DD can protect against LPS-stimulated inflammation and liver injury at least partly by suppression of NF-κB and MAPK signaling pathways.     

Pharmacokinetics of flutamide and its metabolite 2-hydroxyflutamidein normal and hepatic injury rats

目的：建立一新的高压液相色谱法用来研究氟他胺（Ｆｌｕ）及其活性代谢产物２羟基氟他胺（ＨＦ）的药物动力学．方法：正常及肝损伤大鼠灌胃Ｆｌｕ５０ｍｇ·ｋｇ－１．采用反相高压液相色谱法，以甲基睾丸素为内标，流动相为甲醇∶乙腈∶水∶乙醚＝４０∶２０∶３５∶１（体积比），检测波长为２３４ｎｍ．结果：Ｆｌｕ的Ｋ与Ｃｌ分别由０６２±０１６ｈ－１及６０±１０Ｌ·ｋｇ－１·ｈ－１减小到０１６±００３ｈ－１及０６３±０２９Ｌ·ｋｇ－１·ｈ－１（Ｐ＜００１），ＡＵＣ与Ｃｍａｘ分别由８６±１３ｍｇ·Ｌ－１·ｈ及２４±０７ｍｇ·Ｌ－１增加到１００±４４ｍｇ·ｋｇ－１·ｈ及６７±２８ｍｇ·Ｌ－１（Ｐ＜００１）．ＨＦ的Ｋ（ｍ）由００７±００１ｈ－１减小到００５±００１ｈ－１（Ｐ＜００１）．结论：在肝损伤大鼠，Ｆｌｕ与ＨＦ消除受到显著抑制．     

The protective mechanism of QGC in feline esophageal epithelial cells by interleukin-1β treatment

In a previous study, Quercetin-3-O-β-d-glucuronopyranoside (QGC) has anti-oxidative and anti-inflammatory effects in vivo. QGC is a flavonoid glucoside extracted from Rumex Aquaticus. We investigated the downstream target proteins involved in IL-1β-stimulated ROS production and the ability of QGC to inhibit ROS production. Cell viability was determined using the MTT reduction assay. Western blot analysis was performed with antibodies to investigate the activation of three MAPKs, NF-κB, and phosphorylated IκB-α (pIB), and the expression of COX-2. 2′,7′-dichlorofluorescin diacetate was used to detect the generation of intracellular ROS species. When the cells were exposed to media containing IL-1β for 18 h, cell viability was not affected. QGC did not reduce the COX-2 expression induced by IL-1β. However; QGC attenuated the production of intracellular ROS induced by IL-1β. IL-1β increased the expression of ERK, p38 MAPK, and pIB, and nuclear translocation of NF-κB were recovered by the ROS scavenger N-acetyl-l-cysteine (NAC) and QGC, but not by the NADPH oxidase inhibitor diphenylene iodonium. Pretreatment of cells with the ERK inhibitor PD98059, the p38 MAPK inhibitor SB202190, NAC, and QGC attenuated nuclear translocation of NF-κB and activation of pIB. QGC has a scavenging effect on cytokine-induced ROS production, thereby preventing its downstream effects, nuclear translocation of NF-κB, and activation of pIB is mediated by activation of ERK and p38 MAPK, although QGC does not inhibit IL-1β-stimulated COX-2 expression in feline esophageal epithelial cells. The data suggest that QGC exerts anti-oxidative effects and inhibitory effects against esophageal epithelial cells signals by the action of IL-1β treatment.     

Effect of prior stress on interleukin-1β and HPA axis responses to acute stress

Interleukin-1β (IL-1β) level is modulated during multiple stress reactions both in brain structures involved in hypothalamic-pituitary-adrenal (HPA) axis regulation and peripheral systems. Multiple distinct stressors induce different IL-1β and HPA axis responses. The purpose of the present study was to determine if the effect of prior repeated restraint stress on IL-1β levels in prefrontal cortex, hippocampus, hypothalamus and plasma may have an impact on alterations induced in HPA axis responses. Experiments were performed on male Wistar rats which were exposed to 10 min restraint stress twice a day for 3 days. Twenty four hours after the last stress period rats were restrained for 10 min and decapitated at 0, 1, 2 or 3 h after cessation of stress. Control rats were injected ip with saline and some of experimental groups with IL-1β receptor antagonist (IL-1ra). After rapid decapitation, trunk blood was collected and prefrontal cortex, hippocampus and hypothalamus were excised and frozen. Interleukin-1β, adrenocorticotropic hormone (ACTH) and corticosterone (CORT) levels were determined in plasma using commercially available kits and IL-1β levels in brain structures samples were analyzed by western blot procedure. Repeated restraint for 3 days alone did not alter resting plasma levels of IL-1β, and moderately augmented plasma ACTH and CORT levels and IL-1β content in brain structures 24 h after the last restraint. IL-1β antagonist abolished the increase in plasma levels of IL-1β, ACTH and CORT as well as IL-1β in brain structures in response to repeated stress and also reduced these changes induced by 10 min stress. This suggests the selectivity of IL-1β receptors in central and peripheral mechanisms modulating the stress-induced HPA axis responses. These results indicate that repeated stress markedly increases IL-1β production in brain structures involved in HPA axis regulation. The present results support the role of brain and peripheral IL-1β in adaptation of HPA response during prolonged stress.     

What are the progesterone-induced changes of the outcome and the serum markers of injury,oxidant activity and inflammation in diffuse axonal injury patients?

To permit appropriate targeted therapy, the present clinical study was aimed to investigate the effects of progesterone on the outcome and the serum markers of injury, oxidant activity and inflammation in diffuse axonal injury (DAI). Forty-eight male DAI patients were divided into two groups (control and progesterone). Progesterone group received progesterone in dose of 1 mg/kg per 12 h for five days. The outcome was investigated using Extended Glasgow Outcome Scale (GOS-E) and functional independence measure (FIM). The markers of inflammation [interleukin-1β (IL-1β), IL-6, transforming growth factor-β1 (TGF-β1)], injury (brain protein of S-100B), and oxidant activity [malondialdehyde (MDA)] were evaluated in the serum of the patients. Higher GOS-E and FIM scores were observed in progesterone group at the six-month follow-up (P < 0.05 and P < 0.01, respectively). Meanwhile, a reduction in the serum levels of IL-1β, MDA and S-100B was noticed in progesterone group 24 h after injury (P < 0.05, P < 0.001 and P < 0.05, respectively), and there was an increase in serum levels of IL-6 and TGF-β1 (P < 0.01 and P < 0.05, respectively). Also, lower levels of MDA and S-100B, and higher levels of TGF-β1 were observed in progesterone group six days after injury (P < 0.05). According to these findings, progesterone may improve the outcome in DAI patients probably through modulation in the levels of cytokines, and reduction in the injury and oxidant activity.