Role of nuclear factor kappaB in liver health and disease. Clin Sci (Lond). 2010;118:691-705. [PMID: 20350292 DOI: 10.1042/CS20090549]

Engineered Exosomes Carrying Super-Repressor IκB Reduced Biliary Atresia-Induced Liver Fibrosis in Minipig and Mouse Models

Background and Aim: Biliary atresia is a rare, progressive disease that affects the bile ducts in newborns. Persistent bile duct obstruction induces various pathological conditions, including jaundice, inflammation, and liver fibrosis; however, the exact pathogenesis of biliary atresia is not yet fully understood. Nuclear factor-κB (NF-κB) is widely acknowledged as a key regulator in the pathogenesis of hepatitis and liver fibrosis, and extensive research has been conducted to develop strategies to effectively inhibit its activity to mitigate liver damage. Exosome-based therapeutic platforms offer targeted NF-κB inhibition with low immunogenicity and enhanced liver-specific delivery. This study aimed to evaluate the therapeutic efficacy of Exo-SrIκB in treating cholestatic liver fibrosis using experimental animal models. Methods: Exo-SrIκB (an exosome-based therapy containing the super-repressor IκB protein) using EXPLOR technology (Exosome engineering for Protein Loading via Optically Reversible protein-protein interactions) to encapsulate the super repressor IκB (SrIκB) within exosomes. The therapeutic efficacy of Exo-SrIκB was assessed in minipig and mouse models with experimentally induced cholestatic liver disease. Results: Administration of Exo-SrIκB significantly attenuated liver fibrosis progression in both animal models by inhibiting NF-κB nuclear translocation and reducing the expression of fibrotic markers. Treated animals exhibited reduced collagen deposition, lower α-SMA levels, and improved hepatic function compared to untreated controls. Conclusion: Exo-SrIκB effectively suppressed NF-κB signaling and alleviated liver fibrosis in experimental cholestatic liver disease models, suggesting that exosome-based therapeutics may offer a targeted and biocompatible application to managing liver fibrosis and other chronic liver diseases.

Paricalcitol attenuates oxidative stress and inflammatory response in the liver of NAFLD rats by regulating FOXO3a and NFκB acetylation

The lack of therapeutics along with complex pathophysiology made non-alcoholic fatty liver disease (NAFLD) a research hotspot. Studies showed that the deficiency of Vitamin D plays a vital role in NAFLD pathogenesis. While several research studies focused on vitamin D supplementation in NAFLD, there is still a need to understand the regulatory mechanism of direct vitamin D receptor activation in NAFLD. In the present study, we explored the role of direct Vitamin D receptor activation using paricalcitol in choline-deficient high-fat diet-induced NAFLD rat liver and its modulation on protein acetylation. Our results showed that paricalcitol administration significantly reduced the fat accumulation in HepG2 cells and the liver of NAFLD rats. Paricalcitol attenuated the elevated serum level of alanine transaminase, aspartate transaminase, insulin, low-density lipoprotein, triglyceride, and increased high-density lipoprotein in NAFLD rats. Paricalcitol significantly decreased the increased total protein acetylation by enhancing the SIRT1 and SIRT3 expression in NAFLD liver. Further, the study revealed that paricalcitol reduced the acetylation of NFκB and FOXO3a in NAFLD liver along with a decrease in the mRNA expression of IL1β, NFκB, TNFα, and increased catalase and MnSOD. Moreover, total antioxidant activity, glutathione, and catalase were also elevated, whereas lipid peroxidation, myeloperoxidase, and reactive oxygen species levels were significantly decreased in the liver of NAFLD after paricalcitol administration. The study concludes that the downregulation of SIRT1 and SIRT3 in NAFLD liver was associated with an increased acetylated NFκB and FOXO3a. Paricalcitol effectively reversed hepatic inflammation and oxidative stress in NAFLD rats through transcriptional regulation of NFκB and FOXO3a, respectively, by inhibiting their acetylation.

Silymarin: Unveiling its pharmacological spectrum and therapeutic potential in liver diseases-A comprehensive narrative review

Liver diseases, encompassing conditions such as cirrhosis, present a substantial global health challenge with diverse etiologies, including viral infections, alcohol consumption, and non-alcoholic fatty liver disease (NAFLD). The exploration of natural compounds as therapeutic agents has gained traction, notably the herbal remedy milk thistle (Silybum marianum), with its active extract, silymarin, demonstrating remarkable antioxidant and hepatoprotective properties in extensive preclinical investigations. It can protect healthy liver cells or those that have not yet sustained permanent damage by reducing oxidative stress and mitigating cytotoxicity. Silymarin, a natural compound with antioxidant properties, anti-inflammatory effects, and antifibrotic activity, has shown potential in treating liver damage caused by alcohol, NAFLD, drug-induced toxicity, and viral hepatitis. Legalon® is a top-rated medication with excellent oral bioavailability, effective absorption, and therapeutic effectiveness. Its active component, silymarin, has antioxidant and hepatoprotective properties, Eurosil 85® also, a commercial product, has lipophilic properties enhanced by special formulation processes. Silymarin, during clinical trials, shows potential improvements in liver function, reduced mortality rates, and alleviation of symptoms across various liver disorders, with safety assessments showing low adverse effects. Overall, silymarin emerges as a promising natural compound with multifaceted hepatoprotective properties and therapeutic potential in liver diseases.

Rosmarinic acid mitigates acrylamide induced neurotoxicity via suppressing endoplasmic reticulum stress and inflammation in mouse hippocampus

BACKGROUND

Acrylamide (ACR) is a widely used compound that is known to be neurotoxic to both experimental animals and humans, causing nerve damage. The widespread presence of ACR in the environment and food means that the toxic risk to human health can no longer be ignored. Rosmarinic acid (RA), a natural polyphenolic compound extracted from the perilla plant, exhibits anti-inflammatory, antioxidant, and other properties. It has also been demon strated to possess promising potential in neuroprotection. However, its role and potential mechanism in treating ACR induced neurotoxicity are still elusive.

PURPOSE

This study explores whether RA can improve ACR induced neurotoxicity and its possible mechanism.

METHODS

The behavioral method was used to study RA effect on ACR exposed mice's neurological function. We studied its potential mechanism through metabolomics, Nissl staining, HE staining, immunohistochemical analysis, and Western blot.

RESULTS

RA pretreatment reversed the increase in mouse landing foot splay and decrease in spontaneous activity caused by 3 weeks of exposure to 50 mg/kg/d ACR. Further experiments demonstrated that RA could prevent ACR induced neuronal apoptosis, significantly downregulate nuclear factor-κB and tumor necrosis factor-α expression, and inhibit NOD-like receptor protein 3 inflammasome activation, thereby reducing inflammation as confirmed by metabolomics results. Additionally, RA treatment prevented endoplasmic reticulum stress (ERS) caused by ACR exposure, as evidenced by the reversal of significant P-IRE1α,TRAF2,CHOP expression increase.

CONCLUSION

RA alleviates ACR induced neurotoxicity by inhibiting ERS and inflammation. These results provide a deeper understanding of the mechanism of ACR induced neurotoxicity and propose a potential new treatment method.

Sulforaphane Is Protective against Warm Ischemia/Reperfusion Injury and Partial Hepatectomy in Rats

Sulforaphane (SFN) has various beneficial effects on organ metabolism. However, whether SFN affects inflammatory mediators induced by warm hepatic ischemia/reperfusion injury (HIRI) is unclear. To investigate the hepatoprotective effects of SFN using an in vivo model of HIRI and partial hepatectomy (HIRI + PH), rats were subjected to 15 min of hepatic ischemia with blood inflow occlusion, followed by 70% hepatectomy and release of the inflow occlusion. SFN (5 mg/kg) or saline was randomly injected intraperitoneally 1 and 24 h before ischemia. Alternatively, ischemia was prolonged for 30 min to evaluate the effect on mortality. The influence of SFN on the associated signaling pathways was analyzed using the interleukin 1β (IL-1β)-treated primary cultured rat hepatocytes. In the HIRI + PH-treated rats, SFN reduced serum liver enzyme activities and the frequency of pathological liver injury, such as apoptosis and neutrophil infiltration. SFN suppressed tumor necrosis factor-alpha (TNF-α) mRNA expression and inhibited nuclear factor-kappa B (NF-κB) activation by HIRI + PH. Mortality was significantly reduced by SFN. In IL-1β-treated hepatocytes, SFN suppressed the expression of inflammatory cytokines and NF-κB activation. Taken together, SFN may have hepatoprotective effects in HIRI + PH in part by inhibiting the induction of inflammatory mediators, such as TNF-α, via the suppression of NF-κB in hepatocytes.

The Hepatic Antisteatosis Effect of Xanthohumol in High-Fat Diet-Fed Rats Entails Activation of AMPK as a Possible Protective Mechanism

Obesity is the leading cause of non-alcoholic fatty liver disease by provoking hyperglycemia, hyperlipidemia, insulin resistance, oxidative stress, and inflammation. Low activity of AMP-activated protein kinase (AMPK) is linked to obesity, liver injury, and NAFLD. This study involves examining if the anti-steatosis effect of Xanthohumol (XH) in high-fat diet (HFD)-fed rats involves the regulation of AMPK. Adult male rats were divided into five groups (n = 8 each) as control (3.85 kcal/g); XH (control diet + 20 mg/kg), HFD (4.73 kcl/g), HFD + XH (20 mg/kg), and HFD + XH (30 mg/kg) + compound c (cc) (0.2 mg/kg). All treatments were conducted for 12 weeks. Treatment with XH attenuated the gain in body weight, fat pads, fasting glucose, and insulin in HFD rats. It also lowered serum leptin and free fatty acids (FFAs) and improved glucose and insulin tolerances in these rats. It also attenuated the increase in serum livers of liver marker enzymes and reduced serum and hepatic levels of triglycerides (TGs), cholesterol (CHOL), FFAs, as well as serum levels of low-density lipoproteins cholesterol (LDL-c) oxidized LDL-c. XH also reduced hepatic levels of malondialdehyde (MDA), nuclear accumulation of NF-κB, and the levels of tumor necrosis-factor-α (TNF-α) and interleukin-6 (IL-6) while stimulating the nuclear levels of Nrf2 and total levels of glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) in these HFD-fed rats. At the molecular levels, XH increased hepatic mRNA expression and phosphorylation of AMPK (Thr72) and reduced the expression of lipogenic genes SREBP1c and ACC-1. In concomitance, XH reduced hepatic liver droplet accumulation, reduced the number of apoptotic nuclei, and improved the structures of nuclei, mitochondria, and rough endoplasmic reticulum. Co-treatment with CC, an AMPK inhibitor, completely abolished all these effects of XH. In conclusion, XH attenuates obesity and HFD-mediated hepatic steatosis by activating hepatic AMPK.

The role of the canonical nf-κb signaling pathway in the development of acute liver failure

As a clinical emergency with a high mortality rate, the treatment of acute liver failure has been paid attention to by society. At present, liver transplantation is the most effective treatment for acute liver failure, but there is still an insufficient supply of liver sources and a poor prognosis. In view of the current therapeutic development of this disease, more researchers have turned their attention to the research of drugs related to the NF-κB pathway. The NF-κB canonical pathway has been proven to play a role in a variety of diseases, regulating inflammation, apoptosis, and other physiological processes. More and more evidence shows that the NF-κB canonical pathway regulates the pathogenesis of acute liver failure. In this review, we will summarize the regulation process of the NF-κB canonical pathway on acute liver failure, and develop a new way to treat acute liver failure by targeting the components of the pathway.

The Protective Effect and Mechanism of a Phytochemical Extract from the Wild Vegetable Shutou (Crateva unilocularis Buch.) against Acetaminophen-Induced Liver Injury in Mice

Acetaminophen (APAP) abuse is a common public health problem which can cause severe liver damage. However, strategies for dealing with this situation safely and effectively are very limited. The goal of the current work was to evaluate the protection and potential molecular mechanisms of an ethanol extract from shoots of the wild vegetable shutou (Crateva unilocularis Buch.) (ECS) against APAP-induced liver damage in mice. Mice orally received ECS for seven days (300 or 600 mg/kg b.w. per day) before being intraperitoneally injected with APAP (250 mg/kg). Results exhibited that ECS obviously decreased the content of alkaline phosphatase, alanine aminotransferase, aspartate transaminase, and malondialdehyde (p < 0.05). Catalase and superoxide dismutase were notably restored (p < 0.05), and the content of reduced glutathione was obviously increased (p < 0.05). Moreover, ECS significantly inhibited the secretion of interleukin-1β and tumor necrosis factor-α (p < 0.05). Further analyses of the mechanisms showed that ECS may alleviate oxidative stress in the liver by increasing the expression of the nuclear factor erythroid-2-related factor 2 and NADH quinone oxidoreductase 1 proteins, and may suppress liver inflammation by inhibiting the expression of the phosphorylated-inhibitor kappa B alpha/inhibitor kappa B alpha, phosphorylated-nuclear factor κB/nuclear factor κB, and cyclooxygenase-2 proteins. Meanwhile, ECS inhibited hepatocyte apoptosis by enhancing B-cell lymphoma gene 2 and suppressing Bcl-2-associated X protein. In summary, ECS may be used as a dietary supplement to prevent the liver damage caused by APAP abuse.

The bidirectional roles of the cGAS-STING pathway in pain processing: Cellular and molecular mechanisms

Pain is a common clinical condition. However, the mechanisms underlying pain are not yet fully understood. It is known that the neuroimmune system plays a critical role in the pathogenesis of pain. Recent studies indicated that the cyclic-GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway can activate the innate immune system by sensing both extrinsic and intrinsic double-stranded DNA in the cytoplasm, which is involved in pain processing. In this review, we summarise (1) the roles of the cGAS-STING pathway in different pain models, (2) the effect of the cGAS-STING pathway in different cells during pain regulation, and (3) the downstream molecular mechanisms of the cGAS-STING pathway in pain regulation. This review provides evidence that the cGAS-STING pathway has pro- and anti-nociceptive effects in pain models. It has different functions in neuron, microglia, macrophage, and T cells. Its downstream molecules include IFN-I, NF-κB, NLRP3, and eIF2α. The bidirectional roles of the cGAS-STING pathway in pain processing are mediated by regulating nociceptive neuronal sensitivity and neuroinflammatory responses. However, their effects in special brain regions, activation of astrocytes, and the different phases of pain require further exploration.

The predictive role of NF-κB-mediated pro-inflammatory cytokine expression levels in hepatitis B vaccine response

Hepatitis B virus (HBV) infection is a global health problem leading to cirrhosis, hepatocellular carcinoma, and liver failure. The Hepatitis B vaccine plays a significant role in reducing the incidence of HBV worldwide. Approximately 5-10% of vaccinated people do not produce protective antibody levels. Nuclear factor kappa B (NF‑κB) mediates inflammatory responses through pro-inflammatory cytokines. However, the role of the NF‑κB signaling pathway and its association with pro-inflammatory cytokines in hepatitis B vaccine response is unclear. We aimed to assess changes in the IL1A, IL6, IL12A, TNF-α, and NFκB1 expression levels in the non-responder and responder. A total of 32 non-responders and 36 responders were included in the study. The expression level of determined genes was analyzed by RT-PCR. Our results showed that IL1A, IL6, IL12A, and NFκB1 mRNA levels significantly increased in the non-responders compared to the responders (p < .01). Furthermore, there was a significant correlation between IL1A, IL6, TNF-α, and NFκB1 in the non-responder and responders. In conclusion, inflammatory signaling pathways may play an important role in response to HBV vaccine. Therefore, NF‑κB signaling and associated pro-inflammatory cytokine mRNA levels could predict hepatitis B vaccine response. However, the underlying molecular mechanisms of hepatitis B vaccine immunity need further investigation.

STING/NF-κB/IL-6-Mediated Inflammation in Microglia Contributes to Spared Nerve Injury (SNI)-Induced Pain Initiation

Innate immune response acts as the first line of host defense against damage and is initiated following the recognition of pathogen-associated molecular patterns (PAMPs). For double-stranded DNA (dsDNA) sensing, interferon gene stimulator (STING) was discovered to be an integral sensor and could mediate the immune and inflammatory response. Selective STING antagonist C-176 was administered and pain behaviors were assessed following spared nerve injury (SNI)-induced neuropathic pain. The level of serum dsDNA following neuropathic pain was assessed using Elisa analysis. STING signaling pathway, microglia activation, and proinflammatory cytokines were assessed by qPCR, western blots, Elisa, and immunofluorescence staining. STING agonist DMXAA was introduced into BV-2 cells to assess the inflammatory response in microglial cells. dsDNA was significantly increased following SNI and STING/TANK-binding kinase 1 (TBK1)/nuclear factor-kappa B (NF-κB) pathway was activated in vivo and vitro. Early but not the late intrathecal injection of C-176 attenuated SNI-induced pain hypersensitivity, microglia activation, proinflammatory factors, and phosphorylated JAK2/STAT3 in the spinal cord dorsal horn, and the analgesic effect of C-176 was greatly abolished by recombinant IL-6 following SNI. We provided evidence clarifying dsDNA mediated activation of microglia STING signaling pathway, after which promoting expression of proinflammatory cytokines that are required for hyperalgesia initiation in the spinal cord dorsal horn of SNI model. Further analysis showed that microglial STING/TBK1/NF-κB may contribute to pain initiation via IL-6 signaling. Pharmacological blockade of STING may be a promising target in the treatment of initiation of neuropathic pain.

Protective Effect of Rhus chinensis Mill. Fruits on 3,5-Diethoxycarbonyl-1,4-Dihydrocollidine-Induced Cholestasis in Mice via Ameliorating Oxidative Stress and Inflammation

This study focused on the preventive effects of the extracts of Rhus chinensis Mill. (RCM) fruits on cholestasis induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) in mice. The results showed that RCM extracts could significantly ameliorate DDC-induced cholestasis via multiple mechanisms, including (1) alleviating liver damage via enhancing antioxidant capacity, such as increasing the contents of glutathione, superoxide dismutase, and catalase and inhibiting the levels of malondialdehyde; (2) preventing liver inflammation by suppressing NF-κB pathway and reducing proinflammatory cytokines secretion (e.g., tumor necrosis factor-α, interleukin-1β, and interleukin-6); (3) inhibiting liver fibrosis and collagen deposition by regulating the expression of transforming growth factor-β and α-smooth muscle actin; (4) modulating abnormal bile acid metabolism through increasing the expression of bile salt export pump and multidrug resistance-associated protein 2. This study was the first to elucidate the potential preventive effect of RCM extracts on DDC-induced cholestasis in mice from multiple pathways, which suggested that RCM fruits could be considered as a potential dietary supplement to prevent cholestasis.

Traditional Chinese medicine: An important source for discovering candidate agents against hepatic fibrosis

Hepatic fibrosis (HF) refers to the pathophysiological process of connective tissue dysplasia in the liver caused by various pathogenic factors. Nowadays, HF is becoming a severe threat to the health of human being. However, the drugs available for treating HF are limited. Currently, increasing natural agents derived from traditional Chinese medicines (TCMs) have been found to be beneficial for HF. A systemic literature search was conducted from PubMed, GeenMedical, Sci-Hub, CNKI, Google Scholar and Baidu Scholar, with the keywords of "traditional Chinese medicine," "herbal medicine," "natural agents," "liver diseases," and "hepatic fibrosis." So far, more than 76 natural monomers have been isolated and identified from the TCMs with inhibitory effect on HF, including alkaloids, flavones, quinones, terpenoids, saponins, phenylpropanoids, and polysaccharides, etc. The anti-hepatic fibrosis effects of these compounds include hepatoprotection, inhibition of hepatic stellate cells (HSC) activation, regulation of extracellular matrix (ECM) synthesis & secretion, regulation of autophagy, and antioxidant & anti-inflammation, etc. Natural compounds and extracts from TCMs are promising agents for the prevention and treatment of HF, and this review would be of great significance to development of novel drugs for treating HF.

A potential link between plasma short‑chain fatty acids, TNF‑α level and disease progression in non‑alcoholic fatty liver disease: A retrospective study

The onset and progression of non-alcoholic fatty liver disease (NAFLD) remains unclear, but short-chain fatty acids (SCFAs) in circulation may participate in its pathogenesis by acting as inflammation inhibitors. The aim of this retrospective study was to investigate plasma concentrations of general SCFAs in healthy individuals and in patients with distinct stages of NAFLD. Three main SCFAs (including acetate, propionate and butyrate) were analyzed by gas chromatography. The plasma TNF-α concentration was measured by ELISA. One-way ANOVA, Spearman's correlation and Pearson's correlation analysis were performed to estimate the associations between SCFAs, TNF-α and disease progression. Multiple linear stepwise regression was computed to explore the predictor variables of TNF-α in circulation. A total of 71 patients with NAFLD [including 27 patients with NAFL, 20 patients with non-alcoholic steatohepatitis (NASH) and 24 patients with NAFLD-related cirrhosis (NAFLD-cirrhosis)] and 9 healthy control (HC) subjects were enrolled for analysis. Although not statistically significant, plasma SCFAs were elevated in patients with NAFL compared with HC subjects, whereas the vast majority of SCFAs were statistically reduced in patients with NASH or NAFLD-cirrhosis compared with patients with NAFL. Plasma SCFAs had no significant differences in NASH or NAFLD-cirrhosis patients compared with HC subjects. In addition, significant negative correlations were observed between TNF-α and SCFAs. The progression of NAFLD (β=0.849; P<0.001) and the decline of the total three SCFA concentrations (β=-0.189; P<0.001) were recognized as independent risk variables related to the elevated peripheral TNF-α in the multiple linear stepwise regression model. Plasma SCFA concentrations may alter with the development of NAFLD and may have a potential link to TNF-α and the progression of NAFLD, which may serve a protective role toward disease advancement. Further mechanistic studies, such as analysis of gastrointestinal microecology, signaling pathways and functions involved in TNF-α, need to be performed. Also, therapeutic supplementation of SCFAs for NASH and NAFLD-cirrhosis needs further research and verification.

Heparanase-1 is upregulated by hepatitis C virus and favors its replication

BACKGROUND & AIMS

Over time, chronic HCV infection can lead to hepatocellular carcinoma (HCC), a process that involves changes to the liver extracellular matrix (ECM). However, the exact mechanisms by which HCV induces HCC remain unclear. Therefore, we sought to investigate the impact of HCV on the liver ECM, with a focus on heparanase-1 (HPSE).

METHODS

HPSE expression was assessed by quantitative reverse-transcription PCR, immunoblotting and immunofluorescence in liver biopsies infected or not with HCV, and in 10-day-infected hepatoma Huh7.5 cells. Cell lines deficient for or overexpressing HPSE were established to study its role during infection.

RESULTS

HCV propagation led to significant HPSE induction, in vivo and in vitro. HPSE enhanced infection when exogenously expressed or supplemented as a recombinant protein. Conversely, when HPSE expression was downregulated or its activity blocked, HCV infection dropped, suggesting a role of HPSE in the HCV life cycle. We further studied the underlying mechanisms of such observations and found that HPSE favored HCV release by enhancing CD63 synthesis and exosome secretion, but not by stimulating HCV entry or genome replication. We also showed that virus-induced oxidative stress was involved in HPSE induction, most likely through NF-κB activation.

CONCLUSIONS

We report for the first time that HCV infection is favored by HPSE, and upregulates HPSE expression and secretion, which may result in pathogenic alterations of the ECM.

LAY SUMMARY

Chronic hepatitis C virus (HCV) infection can lead to hepatocellular carcinoma development in a process that involves derangement of the extracellular matrix (ECM). Herein, we show that heparanase-1, a protein involved in ECM degradation and remodeling, favors HCV infection and is upregulated by HCV infection; this upregulation may result in pathogenic alterations of the ECM.

Expression of nuclear factor kappa B components in the ovine maternal liver in early pregnancy periods

There is a systemic immunological adaptation to maintaining tolerance towards the allogeneic fetus, and the liver participates in the adaptive immune tolerance during normal pregnancy. Nuclear factor kappa B (NF-κB) signalings contribute to immune regulation and liver homoeostasis. The objective of this study is to explore the effects of early pregnancy on expression of NF-κB components in the maternal liver in sheep. The maternal livers were sampled on Day 16 of the estrous cycle, and Days 13, 16, and 25 of gestation, and the expression of NF-κB components, including NF-κB1 (p50), NF-κB2 (p52), RelA (p65), RelB, and c-Rel, was detected by quantitative real-time polymerase chain reaction (PCR), Western blot analysis, and immunohistochemical analysis. Our data revealed that early pregnancy inhibited the expression of NF-κB1 and c-Rel, but the expression of NF-κB1 and c-Rel was increased during early pregnancy. However, early pregnancy enhanced the expression of NF-κB2, RelA, and RelB with the pregnancy progress. In conclusion, early pregnancy regulates the expression of NF-κB components in the maternal livers, which may contribute to maintaining maternal liver homeostasis and immune tolerance during early pregnancy in sheep.

The protective effect of kirenol in osteoarthritis: an in vitro and in vivo study

BACKGROUND

Osteoarthritis (OA) is a chronic degenerative disease, its main characteristic involves articular cartilage destruction and inflammation response, absent of effective medical treatment. Our current research aimed to explore anti-inflammatory effect of kirenol, a diterpenoid natural product compound, in the development of OA and its potential molecular mechanism through in vitro and in vivo study.

METHODS

In vitro, chondrocytes were pretreated with kirenol for 2 h before IL-1β stimulation. Production of NO, PGE2, TNF-α, IL-6, aggrecan, collagen-II, MMP13and ADAMTS5 were evaluated by the Griess reaction and ELISAs. The mRNA (aggrecan and collagen-II) and protein expression (COX-2, iNOS, P65, IκB, PI3K, AKT) were measured by qRT-PCR and Western blot respectively. Immunofluorescence was used to assess the expression of collagen-II and P65. The in vivo effect of kirenol was evaluated in mice OA models induced by destabilization of the medial meniscus (DMM).

RESULTS

We found that kirenol inhibited IL-1β-induced expression of NO, PGE2, TNF-α, IL-6, COX-2, iNOS, ADAMTS-5. Besides, kirenol remarkably decreased IL-1β-induced degradation of aggrecan and collagen-II. Furthermore, kirenol significantly inhibited IL-1β-induced phosphorylation of PI3K/Akt and NF-κB signaling. In vivo, the cartilage in kirenol-treated mice exhibited less cartilage degradation and lower OARSI scores.

CONCLUSIONS

Taken together, the results of this study provide potent evidence that kirenol could be utilized as a potentially therapeutic agent in prevention and treatment of OA.

Hepatoprotective effects of phytochemicals berberine and umbelliferone against methotrexate-induced hepatic intoxication: experimental studies and in silico evidence

Chemotherapeutic drugs are used effectively to manage wide types of malignancies, but their therapeutic use is limited due to their associated hepatic intoxication. The current study sheds light on the effect of phytochemicals berberine (BBR) and umbelliferone (UMB) on methotrexate (MTX)-induced hepatic intoxication. Forty-eight rats were allocated to normal, BBR (50 mg/kg orally for 10 days), UMB (30 mg/kg orally for 10 days), MTX (20 mg/kg at the 5th day), BBR+MTX, and UMB+MTX. With regard to MTX, the results of this investigation reveal potent amelioration of MTX hepatotoxicity by BBR and UMB through reduction of the elevated serum levels of ALT, ALP, AST, and LDH confirmed by the attenuation of histopathological abrasion in liver tissues. BBR and UMB markedly restored antioxidant status. More importantly, BBR resulted in reducing P₃₈ mitogen-activated protein kinase (P₃₈MAPK), nuclear factor kappa-B (NF-κB), and Kelch-like ECH-associated protein 1 (Keap-1) genes and enhanced mRNA expression of Nrf-2 (P < 0.05). Interestingly, in silico studies via molecular docking pinpointed the binding modes of BBR and UMB to the binding pocket residues of P₃₈MAPK, NF-κB, and Keap-1 and demonstrated a promising inhibition of Keap-1, P₃₈MAPK, and NF-κB. BBR and UMB reduced the expression of pro-apoptotic protein Bax and apoptotic protein caspase-3 as well as increased the expression of anti-apoptotic protein Bcl-2. Therefore, BBR and UMB may denote promising therapeutic agents that can avert hepatic intoxication in patients receiving MTX.

The inhibition of NFкB signaling and inflammatory response as a strategy for blunting bile acid-induced hepatic and renal toxicity

The cholestatic liver injury could occur in response to a variety of diseases or xenobiotics. Although cholestasis primarily affects liver function, it has been well-known that other organs such as the kidney could be influenced in cholestatic patients. Severe cholestasis could lead to tissue fibrosis and organ failure. Unfortunately, there is no specific therapeutic option against cholestasis-induced organ injury. Hence, finding the mechanism of organ injury during cholestasis could lead to therapeutic options against this complication. The accumulation of potentially cytotoxic compounds such as hydrophobic bile acids is the most suspected mechanism involved in the pathogenesis of cholestasis-induced organ injury. A plethora of evidence indicates a role for the inflammatory response in the pathogenesis of several human diseases. Here, the role of nuclear factor-kB (NFkB)-mediated inflammatory response is investigated in an animal model of cholestasis. Bile duct ligated (BDL) animals were treated with sulfasalazine (SSLZ, 10 and 100 mg/kg, i.p) as a potent inhibitor of NFkB signaling. The NFkB proteins family activity in the liver and kidney, serum and tissue levels of pro-inflammatory cytokines, tissue biomarkers of oxidative stress, serum markers of organ injury, and the liver and kidney histopathological alterations and fibrotic changes. The oxidative stress-mediated inflammatory-related indices were monitored in the kidney and liver at scheduled time intervals (3, 7, and 14 days after BDL operation). Significant increase in serum and urine markers of organ injury, besides changes in biomarkers of oxidative stress and tissue histopathology, were evident in the liver and kidney of BDL animals. The activity of NFkB proteins (p65, p50, p52, c-Rel, and RelB) was significantly increased in the liver and kidney of cholestatic animals. Serum and tissue levels of pro-inflammatory cytokines (IL-1β, IL-2, IL-6, IL-7, IL-12, IL-17, IL-18, IL-23, TNF-α, and INF-γ) were also higher than sham-operated animals. Moreover, TGF- β, α-SMA, and tissue fibrosis (Trichrome stain) were evident in cholestatic animals' liver and kidneys. It was found that SSLZ (10 and 100 mg/kg/day, i.p) alleviated cholestasis-induced hepatic and renal injury. The effect of SSLZ on NFkB signaling and suppression of pro-inflammatory cytokines could play a significant role in its protective role in cholestasis. Based on these data, NFkB signaling could receive special attention to develop therapeutic options to blunt cholestasis-induced organ injury.

α-Cyperone (CYP) down-regulates NF-κB and MAPKs signaling, attenuating inflammation and extracellular matrix degradation in chondrocytes, to ameliorate osteoarthritis in mice

Inflammation and extracellular matrix (ECM) degradation have been implicated in the pathological process of osteoarthritis (OA). α-Cyperone is the main active component of the traditional Chinese medicine Cyperus rotundus L. In this study, we found that α-Cyperone abolished the IL-1β-induced production of inflammatory cytokines in isolated rat chondrocytes, such as cyclooxygenase-2 (COX-2), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS), in a dose-dependent manner (0.75, 1.5 or 3 μM). Also, the results showed that α-Cyperone downregulated the expression of metalloproteinases (MMPs) and thrombospondin motifs 5 (ADAMTS5), and upregulated the expression of type-2 collagen. Mechanistically, molecular docking tests revealed that α-Cyperone stably and effectively binds to p65, p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK). α-Cyperone inhibited NF-κB activation by blocking its nuclear transfer, and decreasing the phosphorylation of mitogen-activated protein kinase (MAPKs). In addition, in vivo studies based on a mouse model of arthritis showed that α-Cyperone prevented the development of osteoarthritis. Therefore, α-Cyperone may be a potential anti-OA drug.

Maltol inhibits the progression of osteoarthritis via the nuclear factor-erythroid 2-related factor-2/heme oxygenase-1 signal pathway in vitro and in vivo

Osteoarthritis (OA) is a common degenerative joint disease characterized by articular cartilage degeneration and inflammation. Currently, there is hardly any effective treatment for OA due to its complicated pathology and the severe side effects of the treatment drugs used. It has been reported that maltol, a Maillard reaction product derived from ginseng, inhibits inflammation and oxidative stress in several animal models. However, the potential anti-inflammatory effects of maltol in OA treatment are unknown. This study aimed to evaluate the anti-inflammatory effects of maltol on interleukin (IL)-1β-induced mouse chondrocytes and protective effects of maltol on these chondrocytes in medial meniscus destabilization (DMM) OA mouse models. Mice, randomly divided into maltol (n = 15), vehicle (n = 15) and control (n = 15) groups were treated with the same dose of maltol or saline, respectively. The cartilage tissues were extracted for histological analysis 8 weeks postoperative. For the in vitro studies, chondrocytes were treated with 10 ng mL-1 IL-1β combined with maltol at different concentrations. In vitro assays showed that the maltol pre-treatment significantly inhibited the expressions of multiple inflammatory factors induced by IL-1β, such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), nitric oxide (NO), interleukin-6 (IL-6) and tumor necrosis factor (TNF-α). In addition, maltol alleviated the degradation of the extracellular matrix (ECM) by inhibiting the expressions of matrix metalloproteinase-13 (MMP13) and thrombospondin motif 5 (ADAMTS5), as well as reversing the degradation of aggrecan and collagen II. Moreover, maltol suppressed nuclear factor kappa B (NF-κB) signaling by activating the nuclear factor-erythroid 2-related factor-2 (Nrf2) in in vitro and in vivo studies. These findings indicate that maltol reduces the inflammation induced by IL-1β in chondrocytes. Therefore, the results of this study indicated that maltol may be a potential drug for the effective treatment of OA.

Changes of type II collagenase biomarkers on IL-1β-induced rat articular chondrocytes

Osteoarthritis (OA) is characterized by progressive degeneration of cartilage, formation of cartilage at the cartilage edge, and remodeling of the subchondral bone. Pro-inflammatory cytokines [e.g., interleukin (IL)-1β] that induce inflammation and promote chondrocyte damage induce OA. Currently, the diagnosis of OA is commonly based on imaging examinations (e.g., X-ray) and evaluations of clinical symptoms; however, biomarkers that can effectively diagnose OA are currently not available. By studying the mechanism underlying OA cartilage injury and changes in the concentrations of the biomarkers procollagen type II carboxy-terminal propeptide (PIICP), collagen type-II C-telopeptide fragments (CTX-II), and type II collagen cleavage neoepitope (C2C) during pathogenesis, the present study established a theoretical basis for the evaluation and early diagnosis of OA. In an experiment, 10 ng/ml IL-1β was used to the treat chondrocyte-induced OA models in vitro for 0, 12, 24 and 48 h. Western blotting was used to detect the expression levels of matrix metalloproteinase (MMP)-3, MMP-13, and inducible nitric oxide synthase (iNOS) protein at each time-point. The concentrations of CTX-II, C2C, and PIICP in the cell culture supernatant were detected by ELISA kit. A biochemical kit was used to detect changes of nitric oxide (NO) in the cell culture supernatant. In addition, chondrocytes were treated with 10 ng/ml IL-1β for 0, 30, 60 and 90 min and the translocation and phosphorylation of the NF-κB pathway were investigated by western blotting. Following IL-1β stimulation, the NF-κB pathway was activated to increase the expression levels of MMPs and iNOS synthesis downstream of the pathway, resulting in an increased degradation of type II collagen (Col II). To sum up, pro-inflammatory IL-1β induced an OA chondrocyte model. During the development of OA, the expression of MMPs and NO increased and Col II was degraded.

Silymarin as Supportive Treatment in Liver Diseases: A Narrative Review

Silymarin, an extract from milk thistle seeds, has been used for centuries to treat hepatic conditions. Preclinical data indicate that silymarin can reduce oxidative stress and consequent cytotoxicity, thereby protecting intact liver cells or cells not yet irreversibly damaged. Eurosil 85® is a proprietary formulation developed to maximize the oral bioavailability of silymarin. Most of the clinical research on silymarin has used this formulation. Silymarin acts as a free radical scavenger and modulates enzymes associated with the development of cellular damage, fibrosis and cirrhosis. These hepatoprotective effects were observed in clinical studies in patients with alcoholic or non-alcoholic fatty liver disease, including patients with cirrhosis. In a pooled analysis of trials in patients with cirrhosis, silymarin treatment was associated with a significant reduction in liver-related deaths. Moreover, in patients with diabetes and alcoholic cirrhosis, silymarin was also able to improve glycemic parameters. Patients with drug-induced liver injuries were also successfully treated with silymarin. Silymarin is generally very well tolerated, with a low incidence of adverse events and no treatment-related serious adverse events or deaths reported in clinical trials. For maximum benefit, treatment with silymarin should be initiated as early as possible in patients with fatty liver disease and other distinct liver disease manifestations such as acute liver failure, when the regenerative potential of the liver is still high and when removal of oxidative stress, the cause of cytotoxicity, can achieve the best results.

Chinese Herbal Formula (CHF03) Attenuates Non-Alcoholic Fatty Liver Disease (NAFLD) Through Inhibiting Lipogenesis and Anti-Oxidation Mechanisms

Nonalcoholic fatty liver disease (NAFLD) is a hepatic ailment with a rapidly increasing incidence in the human population due largely to dietary hyper nutrition and subsequent obesity. Discovering effective natural compounds and herbs against NAFLD can provide alternative and complementary medical treatments to current chemical pharmaceuticals. In this study, ICR male mice were fed a high-fat diet (HFD) in vivo and the AML12 cells were treated with palmitic acid (PA) in vitro. We explore the protective effect and potential mechanism of Chinese Herbal Formula (CHF03) against NAFLD by HE staining, transmission Electron Microscopy assay, Western blotting, and gene expression. In vivo, oxidative stress markers (GSH, GSH-px, MDA, SOD, and CAT) confirmed that CHF03 alleviated oxidative stress and abundance of NF-κB proteins indicating a reduction in inflammation and oxidative stress. The lower protein abundance of ACACA and FASN indicated a preventive effect on lipogenesis. Histological and ultrastructural observations revealed that CHF03 inhibited NAFLD. Expression of Srebf1, Fasn, and Acaca, which are associated with lipogenesis, were downregulated. In vitro, genes and proteins are expressed in a dose-dependent manner, consistent with those in the liver. CHF03 inhibited lipid accumulation and expression of NF-κB, nuclear transfer, and transcriptional activity in AML12 cells. The CHF03 might have a beneficial role in the prevention of hepatic steatosis by altering the expression of lipogenic genes and attenuating oxidative stress.

Maltol Improves APAP-Induced Hepatotoxicity by Inhibiting Oxidative Stress and Inflammation Response via NF-κB and PI3K/Akt Signal Pathways

Maltol, a food-flavoring agent and Maillard reaction product formed during the processing of red ginseng (Panax ginseng, C.A. Meyer), has been confirmed to exert a hepatoprotective effect in alcohol-induced oxidative damage in mice. However, its beneficial effects on acetaminophen (APAP)-induced hepatotoxicity and the related molecular mechanisms remain unclear. The purpose of this article was to investigate the protective effect and elucidate the mechanisms of action of maltol on APAP-induced liver injury in vivo. Maltol was administered orally at 50 and 100 mg/kg daily for seven consecutive days, then a single intraperitoneal injection of APAP (250 mg/kg) was performed after the final maltol administration. Liver function, oxidative indices, inflammatory factors—including serum alanine and aspartate aminotransferases (ALT and AST), tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), liver glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA), cytochrome P450 E1 (CYP2E1) and 4-hydroxynonenal (4-HNE) were measured. Results demonstrated that maltol possessed a protective effect on APAP-induced liver injury. Liver histological changes and Hoechst 33258 staining also provided strong evidence for the protective effect of maltol. Furthermore, a maltol supplement mitigated APAP-induced inflammatory responses by increasing phosphorylated nuclear factor-kappa B (NF-κB), inhibitor kappa B kinase α/β (IKKα/β), and NF-kappa-B inhibitor alpha (IκBα) in NF-κB signal pathways. Immunoblotting results showed that maltol pretreatment downregulated the protein expression levels of the B-cell-lymphoma-2 (Bcl-2) family and caspase and altered the phosphorylation of phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) in a dose-dependent manner. In conclusion, our findings clearly demonstrate that maltol exerts a significant liver protection effect, which may partly be ascribed to its anti-inflammatory and anti-apoptotic action via regulation of the PI3K/Akt signaling pathway.

A novel AMPK activator improves hepatic lipid metabolism and leukocyte trafficking in experimental hepatic steatosis

A novel AMP-activated protein kinase (AMPK) activator, IMM-H007 (H007), has been reported to reduce serum lipid levels and inhibit lipid accumulation in the liver in hyperlipidemic animal models. However, how H007 ameliorates hepatic steatosis and inflammation remains unknown. In the present study, H007, at 200 mg/kg, reduced hepatic lipid levels and the levels of collagenous fiber in the liver in high-fat diet (HFD)-fed hamsters compared to those in the HFD group. Meanwhile, compared to the controls, H007 significantly inhibited sterol-regulatory element binding protein (SREBP)-1c and acetyl CoA carboxylase (ACC) expression by upregulating the AMPK activity, suppressing the saturated fatty acid accumulation and increasing polyunsaturated fatty acid synthesis in the liver. Compared to the controls, H007 treatment inhibited the expression of monocyte chemotactic protein (MCP-1) in fatty acid-treated HepG2 cells; suppressed leukocyte adherence and rolling on the liver microvasculature; and suppressed hepatic macrophage infiltration. H007 also suppressed the expression of nuclear factor-κB (NF-κB) p65 in fatty acid- and lipopolysaccharide-treated HepG2 cells compared to that in the controls by activating AMPK. These data suggested that H007 had a beneficial effect by improving the lipid composition in the liver and inhibiting inflammatory cell trafficking in the development of nonalcoholic fatty liver disease.

MicroRNA-125b protects liver from ischemia/reperfusion injury via inhibiting TRAF6 and NF-κB pathway

MicroRNA-125b (miR-125b), which was previously proved to be a potential immunomodulator in various disease, attenuated mouse hepatic ischemia/reperfusion (I/R) injury in this study. miR-125b was decreased in RAW 264.7 cells exposed to hypoxia/reoxygenation (H/R). The expression of IL-1β, IL-6 and TNF-α in both serum and supernate were reduced in miR-125b over-expression groups. The hepatic histopathological changes were reduced in miR-125b agomir groups. In the miR-125b antagomir groups, serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly elevated compared with negative control (NC) groups. The protein expression of TNF receptor-associated factor 6 (TRAF6), IL-1β and the phosphorylation of p65 (p-p65) were suppressed by the up-regulation of miR-125b. Furthermore, the nuclear translocation of p-p65, measured by immunofluorescence, was enhanced by the miR-125b inhibitors. In conclusion, our study indicates that miR-125b protects liver from hepatic I/R injury via inhibiting TRAF6 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signal pathway.

Protective Effect of Meretrix meretrix Oligopeptides on High-Fat-Diet-Induced Non-Alcoholic Fatty Liver Disease in Mice

The present study investigated the effects of MMO (Meretrix meretrix oligopeptides) on mice fed a high-fat diet. Mice were fed either a normal control diet (NC) or a high-fat diet (HFD) without or with MMO (50 mg/kg or 250 mg/kg) for four weeks. Levels of ALT, AST, liver tissue GSH-Px, and SOD activities, MDA levels were measured using commercially available kits; HE staining was performed to analyze pathologic changes of the liver; a TEM assay was performed to measure the ultrastructural alterations of the mitochondria, and Western blotting was performed to detect the expression of gene proteins related to lipid metabolism, inflammation, and liver apoptosis. After six weeks, body weight, ALT, AST, and MDA levels were significantly increased, and GSH-Px levels and SOD activities were significantly decreased in the HFD control group compared with the NC group. Consumption of the HFD compared with the NC caused fatty liver abnormal mitochondria with loss of cristae, intramitochondrial granules, and a swollen and rarefied matrix. Administration of MMO significantly decreased body weight gain, and ALT, AST, and MDA levels; increased SOD activity and GSH-Px levels; alleviated fatty liver steatosis; decreased the early apoptosis population; downregulated SREBP-1c, Bax, Caspase-9, Caspase-3, TNF-α, and NF-κB protein levels; and upregulated PPAR-α, Bcl-2, and AMPK-α, compared with the HFD control group. MMO exhibited protective effects in mice with NAFLD by regulating the NF-κB anti-inflammation signaling pathways to inhibit inflammation, regulate AMPK-α, PPAR-α and SREBP-1c to improve lipid metabolism disorder, and regulate Bcl-2/Bax anti-apoptosis signaling pathways to prevent liver cell apoptosis. These results suggest that dietary supplementation with MMO ameliorates high-fat-diet-induced NAFLD.

Hydroxysafflor yellow A (HSYA) targets the NF-κB and MAPK pathways and ameliorates the development of osteoarthritis

The inflammatory environment has been demonstrated to be strongly associated with the progression of osteoarthritis (OA).

Role and Regulation of p65/β-Catenin Association During Liver Injury and Regeneration: A "Complex" Relationship

An important role for β-catenin in regulating p65 (a subunit of NF-κB) during acute liver injury has recently been elucidated through use of conditional β-catenin knockout mice, which show protection from apoptosis through increased activation of p65. Thus, we hypothesized that the p65/β-catenin complex may play a role in regulating processes such as cell proliferation during liver regeneration. We show through in vitro and in vivo studies that the p65/β-catenin complex is regulated through the TNF-α pathway and not through Wnt signaling. However, this complex is unchanged after partial hepatectomy (PH), despite increased p65 and β-catenin nuclear translocation as well as cyclin D1 activation. We demonstrate through both in vitro silencing experiments and chromatin immunoprecipitation after PH that β-catenin, and not p65, regulates cyclin D1 expression. Conversely, using reporter mice we show p65 is activated exclusively in the nonparenchymal (NPC) compartment during liver regeneration. Furthermore, stimulation of macrophages by TNF-α induces activation of NF-κB and subsequent secretion of Wnts essential for β-catenin activation in hepatocytes. Thus, we show that β-catenin and p65 are activated in separate cellular compartments during liver regeneration, with p65 activity in NPCs contributing to the activation of hepatocyte β-catenin, cyclin D1 expression, and subsequent proliferation.

Inhibitory effects of quercetin on the progression of liver fibrosis through the regulation of NF-кB/IкBα, p38 MAPK, and Bcl-2/Bax signaling

Quercetin, a natural flavonoid, has been used as a nutritional supplement for its anti-inflammatory and antioxidative properties. Quercetin was reported to exhibit a wide range of pharmacological properties, including its effect on anti-hepatic fibrosis. However, the anti-fibrotic mechanisms of quercetin have not been well-characterized to date. This study aimed to investigate the protective effects of quercetin on carbon tetrachloride (CCl₄)-induced liver fibrosis in rats and to clarify its anti-hepatofibrotic mechanisms. We demonstrated that quercetin exhibited in-vivo hepatoprotective and anti-fibrogenic effects against CCl₄-induced liver injury by improving the pathological manifestations, thereby reducing the activities of serum total bilirubin (TBIL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and decreasing the serum levels of hyaluronic acid (HA), laminin (LN), type IV collagen (IV-C) and procollagen III peptide (PIIIP). Furthermore, treatment with quercetin 5-15mg/kg inhibited the activation of NF-κB in a dose-dependent manner via inhibition of IкBα degradation and decreased the expression of p38 MAPK by inhibiting its phosphorylation. Additionally, in a dose-dependent manner, quercetin down-regulated Bax, up-regulated Bcl-2, and subsequently inhibited caspase-3 activation. Moreover, quercetin regulated inflammation factors and hepatic stellate cells (HSCs)-activation markers, such as TNF-α, IL-6, IL-1β, Cox-2, TGF-β, α-SMA, Colla1, Colla2, TIMP-1, MMP-1, and desmin. Taken together, quercetin prevented the progression of liver fibrosis in SD rats. The anti-fibrotic mechanisms of quercetin might be associated with its ability to regulate NF-кB/IкBα, p38 MAPK anti-inflammation signaling pathways to inhibit inflammation, and regulate Bcl-2/Bax anti-apoptosis signaling pathway to prevent liver cell apoptosis.

Histone deacetylases 3 deletion restrains PM2.5-induced mice lung injury by regulating NF-κB and TGF-β/Smad2/3 signaling pathways

Acute lung injury (ALI) as a serious disease with high mortality has been emphasized as a threat to human health and life. Accumulating studies demonstrated that PM2.5 plays a significant role in metabolic and lung diseases. Histone deacetylases 3 (HDAC3) is an important regulator in control of gene transcription, required in up-regulation of inflammation-related signaling, and has been known as a key hotpot in treating a lot of chronic inflammatory diseases. TGF-β/Smad signaling pathway has been proven to be of significance in fibrosis development. Our results found that PM2.5 induced lung function injury in WT mice with a inflammatory responses through the activation of TGF-β/Smad signaling pathways, resulting in lung injury. Of note, HDAC3-deficient mice after PM2.5 administration further promoted TGF-β/Smad signaling pathways activation. In addition, TLR4, p-NF-κB and p-IκBα indicated that HDAC3 knockout mice have a higher inflammation-related signals expression in lung tissue than WT mice after PM2.5 administration, resulting in pro-inflammatory cytokines releasing. Moreover, in vitro experiment of lung epithelial cells challenged with PM2.5, further indicated that TGF-β/Smad2/3 was involved in fibrosis development, leading to inflammation response. Also, the activation of TLR4/NF-κB could be observed in PM2.5-induced lung epithelial cells, leading to inflammation infiltration. These results indicate a new therapeutic target to protect against lung injury caused by PM2.5.

A RelA(p65) Thr505 phospho-site mutation reveals an important mechanism regulating NF-κB-dependent liver regeneration and cancer

Post-translational modifications of nuclear factor (NF)-κB subunits provide a mechanism to differentially regulate their activity in response to the many stimuli that induce this pathway. However, the physiological significance of these modifications is largely unknown, and it remains unclear if these have a critical role in the normal and pathological functions of NF-κB in vivo. Among these, phosphorylation of the RelA(p65) Thr505 residue has been described as an important regulator of NF-κB activity in cell lines, but its physiological significance was not known. Therefore, to learn more about the role of this pathway in vivo, we generated a knockin mouse with a RelA T505A mutation. Unlike RelA knockout mice, the RelA T505A mice develop normally but exhibit aberrant hepatocyte proliferation following liver partial hepatectomy or damage resulting from carbon tetrachloride (CCl4) treatment. Consistent with these effects, RelA T505A mice exhibit earlier onset of cancer in the N-nitrosodiethylamine model of hepatocellular carcinoma. These data reveal a critical pathway controlling NF-κB function in the liver that acts to suppress the tumour-promoting activities of RelA.

HIF-1 α as a Key Factor in Bile Duct Ligation-Induced Liver Fibrosis in Rats

BACKGROUND

Although several studies suggested hypoxia as an important microenvironmental factor contributing to inflammation and fibrosis in chronic liver diseases, the mechanism of this process is not fully understood. We considered hypoxia inducible factor (HIF-1α) as a key transcription factor in liver fibrosis. The aim of the study was to evaluate the mechanisms of signaling pathway during bile duct ligation (BDL)-induced liver fibrosis in rats.

METHODS

BDL animal model of liver fibrosis was used in the study. Male Wistar rats were divided randomly into two experimental groups: sham group (n = 15), BDL group (n = 30). Hydroxyproline (Hyp) content as a marker of collagen accumulation in liver of rats subjected to BDL was evaluated according to the method described by Gerling B et al. Expression of signaling proteins [integrin β₁ receptor, HIF-1α, nuclear factor kappa B (NF-κB), and transforming growth factor (TGF-β)] was evaluated applying Western-immunoblot analysis. In all experiments, the mean values for six assays ± standard deviations (SD) were calculated. The results were submitted to the statistical analysis using the Student's "t" test, accepting p < 0.05 as significant.

RESULTS

Ligation of bile ducts was found to increase Hyp content in rat liver, accompanied by increase of HIF-1α expression during 10 weeks after BDL. The Hyp level was time dependent. There was not such a difference in control group (p < 0.001). Simultaneously expression of NF-κB, TGF-β, β₁-integrin receptor was significantly elevated starting from sixth week after ligation. Activity of metalloproteinases 2 and 9 in the livers were increased 1 week after surgery and remained increased until the end of the experiment.

CONCLUSIONS

The mechanism of development of liver fibrosis involves activation of Matrix metalloproteinase-2 (MMP-2) and Matrix metalloproteinase-9 (MMP-9), upregulation of HIF-1α transcriptional activity and its related factors, NF-κB and TGF-β. It suggests that they may represent targets for the treatment of the disease.

Influence of dietary taurine and housing density on oviduct function in laying hens

Experiments were conducted to study the effects of dietary taurine and housing density on oviduct function in laying hens. Green-shell laying hens were randomly assigned to a free range group and two caged groups, one with low-density and the other with high-density housing. Each group was further divided into control (C) and taurine treatment (T) groups. All hens were fed the same basic diet except that the T groups' diet was supplemented with 0.1% taurine. The experiment lasted 15 d. Survival rates, laying rates, daily feed consumption, and daily weight gain were recorded. Histological changes, inflammatory mediator levels, and oxidation and anti-oxidation levels were determined. The results show that dietary taurine supplementation and reduced housing density significantly attenuated pathophysiological changes in the oviduct. Nuclear factor-κB (NF-κB) DNA binding activity increased significantly in the high-density housing group compared with the two other housing groups and was reduced by taurine supplementation. Tumor necrosis factor-α (TNF-α) mRNA expression in the high-density and low-density C and T groups increased significantly. In the free range and low-density groups, dietary taurine significantly reduced the expression of TNF-α mRNA. Supplementation with taurine decreased interferon-γ (IFN-γ) mRNA expression significantly in the low-density groups. Interleukin 4 (IL-4) mRNA expression was significantly higher in caged hens. IL-10 mRNA expression was higher in the high-density C group than in the free range and low-density C groups. Supplementation with taurine decreased IL-10 mRNA expression significantly in the high-density group and increased superoxide dismutase (SOD) activity in the free range hens. We conclude that taurine has important protective effects against oviduct damage. Reducing housing density also results in less oxidative stress, less inflammatory cell infiltration, and lower levels of inflammatory mediators in the oviduct. Therefore, both dietary taurine and reduced housing density can ameliorate oviduct injury, enhance oviduct health, and promote egg production in laying hens.

Role of interleukin 17 in fatty liver disease and other liver diseases

Fatty liver disease is a lipid metabolism disorder in the liver, with a variety of etiologies which result in the accumulation of fat in the liver. The pathogenesis of fatty liver disease is still unclear and symptomatic treatment is the main method. In recent years, the incidence of fatty liver disease in China is increasing year by year, and the age of onset becomes younger. Recent studies suggest that interleukin 17 (IL-17) is involved not only in the pathogenesis of various diseases, such as autoimmune diseases, inflammatory diseases, and malignant tumors, but also in fatty liver and other liver diseases through inducing insulin resistance, activating some important pathways in the liver, mediating some inflammatory factors and so on. This paper will review the role of IL-17 in fatty liver disease and other liver diseases.

Antifibrotic compounds from Liriodendron tulipifera attenuating HSC-T6 proliferation and TNF-α production in RAW264.7 cells

The inhibition of hepatic stellate cell (HSC) proliferation has been considered as an effective therapeutic target for the treatment of liver fibrosis. The methanolic extract of Liriodendron tulipifera showed significant inhibitory activity against the proliferation of HSCs. Bioactivity-guided isolation afforded twelve compounds including (-)-sesamin (1), (-)-syringaresinol (2), (+)-dihydrodehydrodiconiferyl alcohol (3), salvinal (4), (+)-guaiacylglycerol-8-O-4'-dihydroconiferyl ether (5), (±)-guaiacylglycerol-8-O-4'-sinapyl alcohol ether (6), tanegool (7), (+)-5,5'-dimethoxy-7-oxolariciresinol (8), 3-hydroxy-4-methoxyacetophenone (9), 4-acetoxymethylphenol (10), (-)-paramicholide (11), and blumenol A (12). Among the compounds isolated, 2, 3 and 4 significantly attenuated the proliferation of the activated HSC-T6 cells. The maximal dose of these compounds, however, showed no cytotoxicity in primary cultured rat hepatocytes. Collagen deposition in the activated HSC-T6 cells was reduced by 2, 3 and 4. Also, the increased production of the pro-inflammatory cytokine tumor necrosis factor (TNF)-α induced by lipopolysaccharide was decreased by 3 and 4 in RAW264.7 macrophage cells. Collectively, (-)-syringaresinol (2), (+)-dihydrodehydrodiconiferyl alcohol (3), and salvinal (4) isolated from L. tulipifera leaves and twigs exhibited selective antifibrotic activities toward the activated HSCs and suppressed TNF-α production in RAW264.7 macrophages. These compounds may be useful candidates for developing therapeutic agents for the prevention and treatment of hepatic fibrosis.

Ginkgo biloba extract mitigates liver fibrosis and apoptosis by regulating p38 MAPK, NF-κB/IκBα, and Bcl-2/Bax signaling

Background

Liver fibrosis is the consequence of diverse liver injuries and can eventually develop into liver cirrhosis. Ginkgo biloba extract (GBE) is an extract from dried ginkgo leaves that has many pharmacological effects because of its various ingredients and has been shown to be hepatoprotective.

Purpose and methods

Aimed to investigate the underlying protective mechanisms of GBE on carbon tetrachloride (CCl₄)-induced liver fibrosis in rats. Male Sprague Dawley rats were randomly divided into four groups: control group (C), model group (M), low-dose group (L), and high-dose group (H). Liver fibrosis was induced by CCl₄ groups M, L, and H: group C was administered saline. In addition, GBE at different doses was used to treat groups L and H.

Results

The results of hematoxylin and eosin staining, Masson’s trichrome staining, a liver function index, and a liver fibrosis index showed that GBE application noticeably mitigated fibrosis and improved the function of the liver. The western blotting and immunohistochemistry analyses indicated that GBE reduced liver fibrosis not only by inhibiting p38 MAPK and NF-κBp65 via inhibition of IκBα degradation but also by inhibiting hepatocyte apoptosis via downregulation of Bax, upregulation of Bcl-2, and subsequent inhibition of caspase-3 activation. Inflammation-associated factors and hepatic stellate cell (HSC)-activation markers further demonstrated that GBE could effectively inhibit HSC activation and inflammation as a result of its regulation of p38 MAPK and nuclear factor-kappa B/IκBα signaling.

Conclusion

Our findings indicated a novel role for GBE in the treatment of liver fibrosis. The potential mechanisms may be associated with the following signaling pathways: 1) the p38 MAPK and nuclear factor-kappa B/IκBα signaling pathways (inhibiting inflammation and HSCs activation) and 2) the Bcl-2/Bax signaling pathway (inhibiting the apoptosis of hepatocytes).

AGK enhances angiogenesis and inhibits apoptosis via activation of the NF-κB signaling pathway in hepatocellular carcinoma

High levels of angiogenesis and resistance to apoptosis are major clinical features of hepatocellular carcinoma (HCC), a lethal disease with a high incidence worldwide. However, the precise mechanisms underlying these malignant properties remain unclear. Here, we demonstrated that acylglycerol kinase (AGK) is markedly overexpressed in HCC cell lines and clinical tissues. Immunohistochemical analysis of 245 clinical HCC specimens revealed patients with high levels of AGK expression had poorer overall survival compared to patients with low AGK expression. Furthermore, overexpressing AGK significantly enhanced angiogenesis and inhibited apoptosis in vitro and promoted the tumorigenicity of HCC cells in vivo; silencing endogenous AGK had the opposite effects. Importantly, AGK enhanced angiogenesis and inhibited apoptosis in HCC in part via activation of NF-κB signaling. Our findings provide new evidence that AGK plays an important role in promoting angiogenesis and providing resistance to apoptosis, thus AGK may represent a novel therapeutic target for HCC.

The Cytokinome Profile in Patients with Hepatocellular Carcinoma and Type 2 Diabetes

Understanding the dynamics of the complex interaction network of cytokines, defined as ‘‘cytokinome’’, can be useful to follow progression and evolution of hepatocellular carcinoma (HCC) from its early stages as well as to define therapeutic strategies. Recently we have evaluated the cytokinome profile in patients with type 2 diabetes (T2D) and/or chronic hepatitis C (CHC) infection and/or cirrhosis suggesting specific markers for the different stages of the diseases. Since T2D has been identified as one of the contributory cause of HCC, in this paper we examined the serum levels of cytokines, growth factors, chemokines, as well as of other cancer and diabetes biomarkers in a discovery cohort of patients with T2D, chronic hepatitis C (CHC) and/or CHC-related HCC comparing them with a healthy control group to define a profile of proteins able to characterize these patients, and to recognize the association between diabetes and HCC. The results have evidenced that the serum levels of some proteins are significantly and differently up-regulated in all the patients but they increased still more when HCC develops on the background of T2D. Our results were verified also using a separate validation cohort. Furthermore, significant correlations between clinical and laboratory data characterizing the various stages of this complex disease, have been found. In overall, our results highlighted that a large and simple omics approach, such as that of the cytokinome analysis, supplemented by common biochemical and clinical data, can give a complete picture able to improve the prognosis of the various stages of the disease progression. We have also demonstrated by means of interactomic analysis that our experimental results correlate positively with the general metabolic picture that is emerging in the literature for this complex multifactorial disease.

OSAS-related inflammatory mechanisms of liver injury in nonalcoholic fatty liver disease

Obstructive sleep apnoea syndrome (OSAS) is a common sleep disorder, affecting over 4% of the general population, and is associated with metabolic syndrome and cardiovascular disease, independent of obesity and traditional risk factors. OSAS has been recently connected to nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disease in the world, which can be found in 30% of the general adult population. Several studies suggest that the chronic intermittent hypoxia (CIH) of OSAS patients may per se trigger liver injury, inflammation, and fibrogenesis, promoting NAFLD development and the progression from steatosis to steatohepatitis, cirrhosis, and hepatocellular carcinoma. In NAFLD patients, liver disease may be caused by hypoxia both indirectly by promoting inflammation and insulin resistance and directly by enhancing proinflammatory cytokine production and metabolic dysregulation in liver cells. In this review, we focus on molecular mechanisms linking OSAS to NAFLD, including hypoxia inducible factor (HIF), nuclear factor kappa B (NF-κB), YKL-40, unfolded protein response, and hypoxic adipose tissue inflammation, which all could provide novel potential therapeutic approaches for the management of NAFLD patients with OSAS.

Employment of digital gene expression profiling to identify potential pathogenic and therapeutic targets of fulminant hepatic failure

BACKGROUND

The dysregulated cytokine metabolism and activity are crucial to the development of fulminant hepatic failure (FHF), and many different cytokines have been identified. However, the precise gene expression profile and their interactions association with FHF are yet to be further elucidated.

METHODS

In this study, we detected the digital gene expression profile (DGEP) by high-throughput sequencing in normal and FHF mouse liver, and the candidate genes and potential targets for FHF therapy were verified. And the FHF mouse model was induced by D-Galactosamine (GalN)/lipopolysaccharide (LPS).

RESULTS

Totally 12727 genes were detected, and 3551 differentially expressed genes (DEGs) were obtained from RNA-seq data in FHF mouse liver. In FHF mouse liver, many of those DEGs were identified as differentially expressed in metabolic process, biosynthetic process, response to stimulus and response to stress, etc. Similarly, pathway enrichment analysis in FHF mouse liver showed that many significantly DEGs were also enriched in metabolic pathways, apoptosis, chemokine signaling pathways, etc. Considering the important role of nuclear factor-kappa B (NF-κB) in metabolic regulation and delicate balance between cell survival and death, several DEGs involved in NF-κB pathway were selected for experimental validation. As compared to normal control, NF-κBp65 and its inhibitory protein IκBα were both significantly increased, and NF-κB targeted genes including tumor necrosis factor α(TNFα), inducible nitric oxide synthase (iNOS), interleukin-1β, chemokines CCL3 and CCL4 were also increased in hepatic tissues of FHF. In addition, after NF-κB was successfully pre-blocked, there were significant alteration of hepatic pathological damage and mortality of FHF mouse model.

CONCLUSIONS

This study provides the globe gene expression profile of FHF mouse liver, and demonstrates the possibility of NF-κB gene as a potential therapeutic target for FHF.

CYP2J2 overexpression attenuates nonalcoholic fatty liver disease induced by high-fat diet in mice

Cytochrome P-450 epoxygenase-derived epoxyeicosatrienoic acids (EETs) exert diverse biological activities, which include potent vasodilatory, anti-inflammatory, antiapoptotic, and antioxidatant effects, and cardiovascular protection. Liver has abundant epoxygenase expression and high levels of EET production; however, the roles of epoxygenases in liver diseases remain to be elucidated. In this study, we investigated the protection against high-fat diet-induced nonalcoholic fatty liver disease (NAFLD) in mice with endothelial-specific CYP2J2 overexpression (Tie2-CYP2J2-Tr). After 24 wk of high-fat diet, Tie2-CYP2J2-Tr mice displayed attenuated NAFLD compared with controls. Tie2-CYP2J2-Tr mice showed significantly decreased plasma triglyceride levels and liver lipid accumulation, improved liver function, reduced inflammatory responses, and less increase in hepatic oxidative stress than wild-type control mice. These effects were associated with inhibition of NF-κB/JNK signaling pathway activation and enhancement of the antioxidant defense system in Tie2-CYP2J2-Tr mice in vivo. We also demonstrated that 14,15-EET treatment protected HepG2 cells against palmitic acid-induced inflammation and oxidative stress. 14,15-EET attenuated palmitic acid-induced changes in NF-κB/JNK signaling pathways, malondialdehyde generation, glutathione levels, reactive oxygen species production, and NADPH oxidase and antioxidant enzyme expression in HepG2 cells in vitro. Together, these results highlight a new role for CYP epoxygenase-derived EETs in lipotoxicity-related inflammation and oxidative stress and reveal a new molecular mechanism underlying EETs-mediated anti-inflammatory and antioxidant effects that could aid in the design of new therapies for the prevention and treatment of NAFLD.

Hepatoprotective effects of Limonium tetragonum, edible medicinal halophyte growing near seashores

Background:

During the process of hepatic fibrosis, the activation of hepatic stellate cells (HSCs) is responsible for the increased formation and reduced degradation of extracellular matrix in the liver. By employing the hepatic stellate cell line, HSC-T6, it was found that the methanol extract of Limonium tetragonum, a halophyte living in salt marsh near south and western seashores of Korea significantly inhibited the proliferation of HSC-T6 cells.

Objective:

In the present study, we attempted to investigate the antifibrotic effects of the mathanolic extract of L. tetragonum (MELT) in the activated HSC-T6 cells.

Materials and Methods:

The proliferation of HSC-T6 was stimulated by culturing environment or platelet-derived growth factor (PDGF-BB) insult, and then the inhibitory activities of MELT were measured.

Results:

It was found that MELT suppressed the proliferation of the activated HSC-T6 in concentration- and time-dependent manners. The increased collagen deposition in the activated HSC-T6 cells was also decreased by the treatment of MELT. The maximal dose of MELT, however, had little effect on primary cultured rat hepatocytes. Wlammatory cytokine, tumor necrosis factor alpha (TNF-α) produced by lipopolysaccharide-stimulated RAW264.7 macrophages was inhibited by MELT.

Conclusion:

Collectively, the above results demonstrated that MELT suppressed HSCs proliferation but not in hepatocytes, implying that L. tetragonum may be useful candidates for developing therapeutic agents for the prevention and treatment of hepatic fibrosis.