Molecular mechanisms of hepatic apoptosis regulated by nuclear factors

Deletion of Mixed Lineage Kinase Domain Like Pseudokinase Aggravates Chronic Alcohol-Induced Liver Injury via Increasing Apoptosis

BACKGROUND AND AIM

he mixed lineage kinase domain like pseudokinase (MLKL) is known to play a protective role in non-alcoholic fatty liver disease (NAFLD) via inhibition of necroptosis pathway. However, the role of MLKL in alcoholic liver disease (ALD) is not yet clear.

METHOD

C57BL/6N wild-type (WT) and MLKL-knockout (KO) mice (8-10 weeks old) were randomly divided into eight groups. To establish ALD model of different durations, ethanol (EtOH) was fed to WT and MLKL KO for 10 days, 4 weeks, and 8 weeks. The control group was fed with Lieber-DeCarli control diet for 8 weeks. Mortality, degree of hepatic inflammation, and steatosis were compared among the groups. Bulk mRNA transcriptome analysis was performed. Abundance of transcript and gene expressions were calculated based on read count or Transcript by Million (TPM) value.

RESULTS

Survival rate of MLKL KO mice compared to WT was similar until 4 weeks, but the survival of MLKL KO mice significantly decreased after 8 weeks in ALD model. There was no difference in degree of inflammation, steatosis, and NAS scores between EtOH-fed MLKL KO and EtOH-fed WT mice at 10 days. However, at 4 weeks and 8 weeks, the degree of hepatic steatosis, NAS, and inflammation were increased in MLKL KO mice. RNA transcriptome data showed that fatty acid synthesis, and lipogenesis, mitochondria, and apoptosis-related pathways were upregulated in EtOH-fed MLKL KO mice compared to EtOH-fed WT mice. Although hepatocyte apoptosis (BAX/BCL2 ratio, caspase-3, and TUNEL staining) increased after EtOH intake; however, apoptosis was more significantly increased in EtOH-fed MLKL KO mice compared to the WT group. At the same time, hepatic cFLIP was decreased in EtOH-fed MLKL KO mice compared to the WT group.

CONCLUSION

MLKL deletion did not prevent chronic alcohol-induced liver damage independently of necroptosis and exacerbated hepatic steatosis by increasing hepatocyte apoptosis.

Novel Peptides from Sturgeon Ovarian Protein Hydrolysates Prevent Oxidative Stress-Induced Dysfunction in Osteoblast Cells: Purification, Identification, and Characterization

This study aimed to explore antioxidant peptides derived from sturgeon (Acipenser schrenckii) ovaries that exhibit antiosteoporotic effects in oxidative-induced MC3T3-E1 cells. The F3-15 component obtained from sturgeon ovarian protein hydrolysates (SOPHs) via gel filtration and RP-HPLC significantly increased the cell survival rate (from 49.38 ± 2.88 to 76.26 ± 2.09%). Two putative antioxidant-acting peptides, FDWDRL (FL6) and FEGPPFKF (FF8), were screened from the F3-15 faction via liquid chromatography-tandem mass spectrometry (LC-MS/MS) and through prediction by computer simulations. Molecular docking results indicated that the possible antioxidant mechanisms of FL6 and FF8 involved blocking the active site of human myeloperoxidase (hMPO). The in vitro tests showed that FL6 and FF8 were equally adept at reducing intracellular ROS levels, increasing the activity of antioxidant enzymes, and protecting cells from oxidative injuries by inhibiting the mitogen-activated protein kinase (MAPK) pathway and activating the phosphoinositide-3 kinase (PI3K)/protein kinase B (AKT)/glycogen synthase kinase-3β (GSK-3β) signaling pathway. Moreover, both peptides could increase differentiation and mineralization abilities in oxidatively damaged MC3T3-E1 cells. Furthermore, FF8 exhibited high resistance to pepsin and trypsin, showcasing potential for practical applications.

Lycopene attenuates chlorpyrifos-induced hepatotoxicity in rats via activation of Nrf2/HO-1 axis

Chlorpyrifos (CPF), is an organophosphate pesticide that is widely used for agricultural purposes. However, it has well-documented hepatotoxicity. Lycopene (LCP) is a plant-derived carotenoid with antioxidant and anti-inflammatory activities. The present work was designed to evaluate the potential hepatoprotective actions of LCP against CPF-induced hepatotoxicity in rats. Animals were assigned into five groups namely: Group I (Control), Group II (LCP), Group III (CPF), Group IV (CPF + LCP 5 mg/kg), and Group V (CPF + LCP 10 mg/kg). LCP offered protection as evidenced by inhibiting the rise in serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) induced by CPF. This was confirmed histologically as LCP-treated animals showed liver tissues with less proliferation of bile ducts and periductal fibrosis. LCP significantly prevented the rise in hepatic content of malondialdehyde (MDA), depletion of reduced glutathione (GSH), and exhaustion of glutathione-s-transferase (GST) and superoxide dismutase (SOD). Further, LCP significantly prevented hepatocyte death as it ameliorated the increase in Bax and the decrease in Bcl-2 expression induced by CPF in liver tissues as determined immunohistochemically. The observed protective effects of LCP were further confirmed by a significant enhancement in heme oxygenase-1 (HO-1) and NF-E2-related factor 2 (Nrf2) expression. In conclusion, LCP possesses protective effects against CPF-induced hepatotoxicity. These include antioxidation and activation of the Nrf2/HO-1 axis.

Research Progress of Programmed Cell Death Induced by Acrylamide

Acrylamide exposure through environment pollution and diet is very common in daily life. With the deepening of the study on the toxicity of acrylamide, it has attracted widespread attention for the effects of acrylamide on multiple organs through affecting a variety of programmed cell death. Multiple studies have shown that acrylamide could exert its toxic effect by inducing programmed cell death, but its specific molecular mechanism is still unclear. In this review, the research on the main forms of programmed cell death (apoptosis, autophagy, and programmed necrosis) induced by acrylamide and their possible mechanisms are reviewed. This review may provide basic data for further research of acrylamide and prevention of its toxicity.

RETRACTED: Adenine Combined with Cisplatin Promotes Anticancer Activity against Hepatocellular Cancer Cells through AMPK-Mediated p53/p21 and p38 MAPK Cascades

Cisplatin has been widely used in cancer treatments. Recent evidence indicates that adenine has potential anticancer activities against various types of cancers. However, the effects of the combination of adenine and cisplatin on hepatocellular carcinoma (HCC) cells remain sketchy. Here, our objective was to elucidate the anticancer activity of adenine in combination with cisplatin in HCC cells and its mechanistic pathways. Cell viability and cell cycle progression were assessed by the SRB assay and flow cytometry, respectively. Apoptosis was demonstrated by PI/annexin V staining and flow cytometric analysis. Protein expression, signaling cascade, and mRNA expression were analyzed by Western blotting and quantitative RT-PCR, respectively. Our results showed that adenine jointly potentiated the inhibitory effects of cisplatin on the cell viability of SK-Hep1 and Huh7 cells. Further investigation showed that adenine combined with cisplatin induced higher S phase arrest and apoptosis in HCC cells. Mechanically, adenine induced AMPK activation, reduced mTOR phosphorylation, and increased p53 and p21 levels. The combination of adenine and cisplatin synergistically reduced Bcl-2 and increased PUMA, cleaved caspase-3, and PARP in HCC cells. Adenine also upregulated the mRNA expression of p53, p21, PUMA, and PARP, while knockdown of AMPK reduced the increased expression of these genes. Furthermore, adenine also induced the activation of p38 MAPK through AMPK signaling, and the inhibition of p38 MAPK reduced the apoptosis of HCC cells with exposure to adenine combined with cisplatin. Collectively, these findings reveal that the combination of adenine and cisplatin synergistically enhances apoptosis of HCC cells, which may be attributed to the AMPK-mediated p53/p21 and p38 MAPK cascades. It suggests that adenine may be a potential adjuvant for the treatment of HCC in combination with cisplatin.

The functional mechanism of bone marrow-derived mesenchymal stem cells in the treatment of animal models with Alzheimer's disease: crosstalk between autophagy and apoptosis

The transplantation of bone marrow-derived mesenchymal stem cells (BMMSCs) alleviates neuropathology and improves cognitive deficits in animal models with Alzheimer's disease. However, the underlying mechanism remains undefined. Based on meta-analysis and comprehensive review, high-profile studies support the theory that transplanted BMMSCs activate autophagy, as evidenced by the expression levels of signal molecules such as Beclin-1, Atg5, LC3-II, and mTOR. Functional autophagy mitigates neuronal apoptosis, which is reflected by the alterations of IAPs, Bcl-2, caspase-3, and so forth. Moreover, the transplantation of BMMSCs can decrease aberrant amyloid-beta peptides as well as tau aggregates, inhibit neuroinflammation, and stimulate synaptogenesis. There is a signal crosstalk between autophagy and apoptosis, which may be regulated to produce synergistic effect on the preconditioning of stem cells. Forasmuch, the therapeutic effect of transplanted BMMSCs can be enhanced by autophagy and/or apoptosis modulators.

Hepatoprotective effect of diallyl trisulfide against lipopolysaccharide and D-galactosamine induced acute liver failure in mice via suppressing inflammation and apoptosis

Acute liver failure (ALF), characterized by the quick occurrence of disorder in liver, is a serious liver injury with extremely high mortality. Therefore, we investigated whether diallyl trisulfide (DATS), a natural product from garlic, protected against ALF in mice and studied underlying mechanisms. In the present study, lipopolysaccharide (LPS) (10 μg·kg^-1)/D-galactosamine (D-gal) (500 mg·kg^-1) was intraperitoneally injected to ICR mice to induce ALF. The mice were orally administered 20-, 40-, or 80-mg·kg^-1 DATS) 1 h before LPS/D-gal exposure. Serum biochemical analyses and pathological study found that DATS pretreatment effectively prevented the ALF in LPS/D-gal-treated mice. Mechanistically, pretreatment of DATS inhibited the increase of the numbers of CD11b⁺ Kupffer cells and other macrophages in the liver, the release of tumor necrosis factor-α into the blood, and Caspase-1 activation induced by LPS/D-gal treatment in mice. Furthermore, DATS inhibited the activation of Caspase-3, downregulation of Bcl-2/Bax ratio, and increase of TUNEL positive staining. Altogether, our findings suggest that DATS exhibits hepatoprotective effects against ALF elicited by LPS/D-gal challenge, which probably associated with anti-inflammation and anti-apoptosis.

Drug-Induced Liver Injury: Clinical Evidence of N-Acetyl Cysteine Protective Effects

Oxidative stress is a key pathological feature implicated in both acute and chronic liver diseases, including drug-induced liver injury (DILI). The latter describes hepatic injury arising as a direct toxic effect of administered drugs or their metabolites. Although still underreported, DILI remains a significant cause of liver failure, especially in developed nations. Currently, it is understood that mitochondrial-generated oxidative stress and abnormalities in phase I/II metabolism, leading to glutathione (GSH) suppression, drive the onset of DILI. N-Acetyl cysteine (NAC) has attracted a lot of interest as a therapeutic agent against DILI because of its strong antioxidant properties, especially in relation to enhancing endogenous GSH content to counteract oxidative stress. Thus, in addition to updating information on the pathophysiological mechanisms implicated in oxidative-induced hepatic injury, the current review critically discusses clinical evidence on the protective effects of NAC against DILI, including the reduction of patient mortality. Besides injury caused by paracetamol, NAC can also improve liver function in relation to other forms of liver injury such as those induced by excessive alcohol intake. The implicated therapeutic mechanisms of NAC extend from enhancing hepatic GSH levels to reducing biomarkers of paracetamol toxicity such as keratin-18 and circulating caspase-cleaved cytokeratin-18. However, there is still lack of evidence confirming the benefits of using NAC in combination with other therapies in patients with DILI.

Hepatocyte Nuclear Factor 4 alpha 2 Messenger RNA Reprograms Liver-Enriched Transcription Factors and Functional Proteins in End-Stage Cirrhotic Human Hepatocytes

The only definitive therapy for end-stage liver disease is whole-organ transplantation. The success of this intervention is severely limited by the complexity of the surgery, the cost of patient care, the need for long-term immunosuppression, and the shortage of donor organs. In rodents and humans, end-stage degeneration of hepatocyte function is associated with disruption of the liver-specific transcriptional network and a nearly complete loss of promoter P1-driven hepatocyte nuclear factor 4-alpha (P1-HNF4α) activity. Re-expression of HNF4α2, the predominant P1-HNF4α, reinstates the transcriptional network, normalizes the genes important for hepatocyte function, and reverses liver failure in rodents. In this study, we tested the effectiveness of supplementary expression of human HNF4α2 messenger RNA (mRNA) in primary human hepatocytes isolated from explanted livers of patients who underwent transplant for end-stage irreversibly decompensated liver failure (Child-Pugh B, C) resulting from alcohol-mediated cirrhosis and nonalcoholic steatohepatitis. Re-expression of HNF4α2 in decompensated cirrhotic human hepatocytes corrects the disrupted transcriptional network and normalizes the expression of genes important for hepatocyte function, improving liver-specific protein expression. End-stage liver disease in humans is associated with both loss of P1-HNF4α expression and failure of its localization to the nucleus. We found that while HNF4α2 re-expression increased the amount of P1-HNF4α protein in hepatocytes, it did not alter the ability of hepatocytes to localize P1-HNF4α to their nuclei. Conclusion: Re-expression of HNF4α2 mRNA in livers of patients with end-stage disease may be an effective therapy for terminal liver failure that would circumvent the need for organ transplantation. The efficacy of this strategy may be enhanced by discovering the cause for loss of nuclear P1-HNF4α localization in end-stage cirrhosis, a process not found in rodent studies.

The effect of Crocin on TFAM and PGC-1α expression and Catalase and Superoxide dismutase activities following cholestasis-induced neuroinflammation in the striatum of male Wistar rats

Bile secretion is a physiological function that is disrupted following Bile Duct Ligation (BDL) and induces cholestasis. Cholestasis is a bile flow reduction that induces apoptosis, oxidative stress, and inflammation, and alters the expression of genes. Evidence shows the relationship between cholestasis and neuroinflammation. Cholestasis via attenuating mitochondrial biogenesis and anti-oxidant activity can induce neuroinflammation and apoptosis. Mitochondrial transcriptional factor A (TFAM) and Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) are involved in mitochondrial biogenesis, and TFAM, PGC-1α, Catalase (CAT), and Superoxide dismutase (SOD) have a role in upregulating antioxidant pathways. On the other hand, many studies have shown the neuroprotective effects of Crocin, the water-soluble carotenoid of Saffron (Crocus sativus L.). In this study, we aimed to investigate the effect of Crocin on the level of TFAM, PGC-1α, CAT, and SOD following cholestasis-induced neuroinflammation in the rat's striatum. Cholestasis was induced by BDL surgery and administration of Crocin was intraperitoneal, at the dose of 30 mg/kg every day, 24 h after BDL surgery up to thirty days. The results showed that TFAM, PGC-1α, and SOD were decreased following cholestasis; while, CAT was increased. In addition, Crocin restored the effects of cholestasis on the level of TFAM, PGC-1α, and SOD. In conclusion, Crocin may have improvement effects on cholestasis-induced neuroinflammation in the rat's striatum.

Activation of PKM2 metabolically controls fulminant liver injury via restoration of pyruvate and reactivation of CDK1

Accumulating evidence indicates that metabolic events profoundly modulate the progression of various diseases. Pyruvate is a central metabolic intermediate in glucose metabolism. In the present study, the metabolic status of pyruvate and its pharmacological significance has been investigated in mice with lipopolysaccharide/D-galactosamine (LPS/D-Gal)-induced fulminant liver injury. Our results indicated that LPS/D-Gal exposure decreased the activity of pyruvate kinase and the content of pyruvate, which were reversed by the PKM2 activator TEPP-46. Pretreatment with TEPP-46 or supplementation with the cell-permeable pyruvate derivate ethyl pyruvate (EP) attenuated LPS/D-Gal-induced liver damage. Interestingly, post-insult intervention of pyruvate metabolism also resulted in beneficial outcomes. The phospho-antibody microarray analysis and immunoblot analysis found that the inhibitory phosphorylation of cyclin dependent kinase 1 (CDK1) was reversed by TEPP-46, DASA-58 or EP. In addition, the therapeutic benefits of PKM2 activator or EP were blunted by the CDK1 inhibitor Ro 3306. Our data suggests that LPS/D-Gal exposure-induced decline of pyruvate might be a novel metabolic mechanism underlies the development of LPS/D-Gal-induced fulminant liver injury, PKM2 activator or pyruvate derivate might have potential value for the pharmacological intervention of fulminant liver injury.

The Effect of NeuroAid (MLC901) on Cholestasis-Induced Spatial Memory Impairment with Respect to the Expression of BAX, BCL-2, BAD, PGC-1α and TFAM Genes in the Hippocampus of Male Wistar Rats

Cholestasis is a bile flow reduction that is induced following Bile Duct Ligation (BDL). Cholestasis impairs memory and induces apoptosis. Apoptosis consists of two pathways: intrinsic and extrinsic. The intrinsic pathway is modulated by BCL-2 (B cell lymphoma-2) family proteins. BCL-2 (a pro-survival BCL-2 protein) has anti-apoptotic effect, while BAD (BCL-2-associated death) and BAX (BCL-2-associated X), the other members of BCL-2 family have pro-apoptotic effect. Furthermore, TFAM (mitochondrial transcriptional factor A) is involved in transcription and maintenance of mitochondrial DNA and PGC-1α (peroxisome proliferator-activated receptor γ coactivator-1α) is a master regulator of mitochondrial biogenesis. On the other hand, NeuroAid is a Traditional Chinese Medicine with neuroprotective and anti-apoptosis effects. In this study, we evaluated the effect of cholestasis on spatial memory and expression of BCL-2, BAD, BAX, TFAM, and PGC-1α in the hippocampus of rats. Additionally, we assessed the effect of NeuroAid on cholestasis-induced cognitive and genetic alterations. Cholestasis was induced by BDL surgery and NeuroAid was injected intraperitoneal at the dose of 0.4 mg/kg. Furthermore, spatial memory was evaluated using Morris Water Maze (MWM) apparatus. The results showed cholestasis impaired spatial memory, increased the expression of BAD and BAX, decreased the expression of TFAM and PGC-1α, and did not alter the expression of BCL-2. Also, NeuroAid decreased the expression of BAD and BAX and increased the expression of TFAM, PGC-1α, and BCL-2. In conclusion, cholestasis impaired spatial memory and increased the expression of pro-apoptotic genes. Also, cholestasis decreased the expression of TFAM and PGC-1α. Interestingly, NeuroAid restored the effects of cholestasis.

FOXA2 inhibits doxorubicin-induced apoptosis via transcriptionally activating HBP rate-limiting enzyme GFPT1 in HCC cells

Apoptosis plays an important role in both carcinogenesis and cancer treatment. Understanding the mechanisms through which resistance to apoptosis occurs in cancer cells has huge implications for cancer treatment. Although pieces of evidence have shown that elevated levels of global O-GlcNAcylation play an anti-apoptotic role in myriad cancers, the underlying mechanism is still ambiguous. In this study, we demonstrated that FOXA2, an essential transcription factor for liver homeostasis and hepatocellular carcinoma (HCC) development, inhibits doxorubicin (DOX)-induced apoptosis through elevating cellular O-GlcNAcylation in HCC cells. In response to DOX treatment, elevated FOXA2 and global O-GlcNAcylation level was observed in HCC cells, and higher FOXA2 levels indicated lower levels of DOX-induced apoptosis. Subsequently, we demonstrated that FOXA2 is a direct transcriptional activator of the hexosamine biosynthetic pathway (HBP) rate-limiting enzyme GFPT1. The upregulation of FOXA2 expression induced the synthesis of intracellular UDP-GlcNAc, which is the sugar substrate of O-GlcNAcylation produced by the HBP. The flux through the HBP elevated the global O-GlcNAcylation level and led to the activation of survival signaling pathways in HCC cells. Furthermore, GFPT1 was proved to be an important downstream regulator of FOXA2-mediated apoptotic suppression. These results provide insights into the molecular mechanism by which FOXA2 inhibits DOX-induced HCC cell apoptosis and suggest that targeting FOXA2 might offer a new strategy for HCC treatment.

Inhibiting roles of FOXA2 in liver cancer cell migration and invasion by transcriptionally suppressing microRNA-103a-3p and activating the GREM2/LATS2/YAP axis

Forkhead box A2 (FOXA2) has emerged as a tumor inhibitor in several human malignancies. This work focused on the effect of FOXA2 on liver cancer (LC) cell invasion and migration and the involving molecules. FOXA2 expression in LC tissues and cell lines was determined. The potential target microRNA (miRNA) of FOXA2 was predicted via bioinformatic analysis and validated through a ChIP assay. The mRNA target of miRNA-103a-3p was predicted via bioinformatic analysis and confirmed via a luciferase assay. Altered expression of FOXA2, miR-103a-3p and GREM2 was introduced in cells to identify their roles in LC cell migration and invasion. Consequently, FOXA2 and GREM2 were poorly expressed while miR-103a-3p was highly expressed in LC samples. Overexpression of FOXA2 or GREM2 suppressed migration and invasion of LC cells, while up-regulation of miR-103a-3p led to inverse trends. FOXA2 transcriptionally suppressed miR-103a-3p to increase GREM2 expression. Silencing of GREM2 blocked the effects of FOXA2. GREM2 increased LATS2 activity and YAP phosphorylation and degradation. To conclude, this study demonstrated that FOXA2 suppressed miR-103a-3p transcription to induce GREM2 upregulation, which increased LATS2 activity and YAP phosphorylation to inhibit migration and invasion of LC cells.

Drug-induced liver injury: Oltipraz and C2-ceramide intervene HNF-1α/GSTA1 expression via JNK signaling pathway

Drug-induced liver injury (DILI) is a serious and frequently occurring issue in drug development. The c-Jun N-terminal kinase (JNK) signaling pathway plays an important role in many diseases; hepatocyte nuclear factor-1α (HNF-1α) and glutathione S-transferase A1 (GSTA1) are important in regulating liver-specific genes expressions and affecting drug metabolism. Oltipraz is used to treat liver cirrhosis by improving liver function, and C2-ceramide is a pro-apoptotic lipid that regulates multiple signaling pathways. In this study, we investigated the function of the JNK signaling pathway with HNF-1α and GSTA1 in a cellular model of DILI and whether oltipraz and C2-ceramide exert effects via the JNK pathway. The results showed that inhibiting JNK could ameliorate APAP-induced hepatocyte injury, reduced oxidative stress, suppressed JNK and c-Jun activation, and hepatocyte apoptosis. Meanwhile, the mRNA and protein expressions of HNF-1α and GSTA1 were increased significantly compared to control conditions. The effect of oltipraz (8 μmol/L) was similar to a JNK inhibitor and significantly increased HNF-1α/GSTA1 expression, but oltipraz combined with JNK inhibitor did not show a synergistic effect. Although C2-ceramide (8 μmol/L) aggravated hepatocyte injury and apoptosis, exacerbated oxidative stress, increased phosphorylation of JNK and c-Jun, and markedly decreased HNF-1α/GSTA1 expression, C2-ceramide combined with JNK inhibitor could partially alleviate these alterations. These results demonstrated that the JNK signaling pathway with HNF-1α/GSTA1 are involved in the process of DILI. Inhibiting JNK up-regulated HNF-1α and GSTA1 expressions which could attenuate hepatocyte injury. Oltipraz and C2-ceramide might affect the expression of HNF-1α/GSTA1 though JNK signaling.

Therapeutic options of TCM for organ injuries associated with COVID-19 and the underlying mechanism

BACKGROUND

Coronavirus disease-2019 (COVID-19) caused by infection with severe acute respiratory coronavirus-2 (SARS-CoV-2) has been spreading rapidly throughout China and in other countries since the end of 2019. The World Health Organization (WHO) has declared that the epidemic is a public health emergency of international concerns. The timely and appropriate measures for treating COVID-19 in China, which are inseparable from the contribution of traditional Chinese medicine (TCM), have won much praise of the world.

PURPOSE

This review aimed to summarize and discuss the essential role of TCM in protecting tissues from injuries associated with COVID-19, and accordingly to clarify the possible action mechanisms of TCM from the perspectives of anti-inflammatory, antioxidant and anti-apoptotic effects.

METHODS

Electronic databases such as Pubmed, ResearchGate, Science Direct, Web of Science, medRixv and Wiley were used to search scientific literatures.

RESULTS

The present review found that traditional Chinese herbs commonly used for the clinical treatment of organ damages caused by COVID-19, such as Scutellaria baicalensis, Salvia miltiorrhizaSalvia miltiorrhiza, and ginseng, could act on multiple signaling pathways involved in inflammation, oxidative stress and apoptosis.

CONCLUSION

TCM could protect COVID-19 patients from tissue injuries, a protection that might be, at least partially, attributed to the anti-inflammatory, antioxidant and anti-apoptotic effects of the TCM under investigation. This review provides evidence and support for clinical treatment and novel drug research using TCM.

Reclassifying Hepatic Cell Death during Liver Damage: Ferroptosis-A Novel Form of Non-Apoptotic Cell Death?

Ferroptosis has emerged as a new type of cell death in different pathological conditions, including neurological and kidney diseases and, especially, in different types of cancer. The hallmark of this regulated cell death is the presence of iron-driven lipid peroxidation; the activation of key genes related to this process such as glutathione peroxidase-4 (gpx4), acyl-CoA synthetase long-chain family member-4 (acsl4), carbonyl reductase [NADPH] 3 (cbr3), and prostaglandin peroxidase synthase-2 (ptgs2); and morphological changes including shrunken and electron-dense mitochondria. Iron overload in the liver has long been recognized as both a major trigger of liver damage in different diseases, and it is also associated with liver fibrosis. New evidence suggests that ferroptosis might be a novel type of non-apoptotic cell death in several liver diseases including non-alcoholic steatohepatitis (NASH), alcoholic liver disease (ALD), drug-induced liver injury (DILI), viral hepatitis, and hemochromatosis. The interaction between iron-related lipid peroxidation, cellular stress signals, and antioxidant systems plays a pivotal role in the development of this novel type of cell death. In addition, integrated responses from lipidic mediators together with free iron from iron-containing enzymes are essential to understanding this process. The presence of ferroptosis and the exact mechanisms leading to this non-apoptotic type of cell death in the liver remain scarcely elucidated. Recognizing ferroptosis as a novel type of cell death in the liver could lead to the understanding of the complex interaction between different types of cell death, their role in progression of liver fibrosis, the development of new biomarkers, as well as the use of modulators of ferroptosis, allowing improved theranostic approaches in the clinic.

The Underlying Mechanisms of Curcumin Inhibition of Hyperglycemia and Hyperlipidemia in Rats Fed a High-Fat Diet Combined With STZ Treatment

Curcumin is the main secondary metabolite of Curcuma longa and other Curcuma spp, and has been reported to have some potential in preventing and treating some physiological disorders. This study investigated the effect of curcumin in inhibiting high-fat diet and streptozotocin (STZ)-induced hyperglycemia and hyperlipidemia in rats. Twenty-six male Sprague-Dawley (SD) rats (170–190 g) were randomly divided into a standard food pellet diet group (Control group), a high-fat diet and streptozotocin group (HF + STZ group), and a high-fat diet combined with curcumin and STZ group (HF + Cur + STZ group). Compared with the HF + STZ group, the HF + Cur + STZ group exhibited significantly reduced fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), alanine aminotransferase (AST), and aspartate transaminase (ALT) levels, as well as liver coefficients. In the livers of these rats, the expression of malondialdehyde (MDA) and Bax was downregulated, whereas that of superoxide dismutase (SOD) and Bcl-2 was upregulated. Moreover, the liver histology of these rats was improved and resembled that of the control rats. These results suggest that curcumin prevents high-fat diet and STZ-induced hyperglycemia and hyperlipidemia, mainly via anti-oxidant and anti-apoptotic mechanisms in the liver.

Adenine inhibits growth of hepatocellular carcinoma cells via AMPK-mediated S phase arrest and apoptotic cascade

Background: Adenine exhibits potential anticancer activity against several types of malignancies. However, whether adenine has anticancer effects on hepatocellular carcinoma (HCC) cells is incompletely explored. Methods: Human HCC cell lines HepG2 and SK-Hep-1 (p53-wild type) and Hep3B (p53-deficient) were used as cell model. Cell growth and cell cycle distribution were determined using MTT assay and flow cytometric analysis, respectively. Protein expression and phosphorylation were assessed by Western blot. Involvement of AMP-activated protein kinase (AMPK) was evaluated using specific inhibitor and small inhibitory RNA (siRNA). Results: Adenine treatments (0.5 - 2 mM) clearly decreased the cell growth of Hep G2 and SK-Hep-1 cells to 72.5 ± 3.4% and 71.3 ± 4.6% of control, respectively. In parallel, adenine also induced sub-G1 and S phase accumulation in both HCC cells. However, adenine did not affect the cell growth and cell cycle distribution of Hep3B cell. Western blot analysis showed that adenine reduced expression of cyclin A/D1 and cyclin-dependent kinase (CDK)2 and upregulated p53, p21, Bax, PUMA, and NOXA in HepG2 cell. Moreover, adenine induced AMPK activation that was involved in the p53-associated apoptotic cascade in HepG2 cells. Inhibition of AMPK activation or knockdown of AMPK restored the decreased cell growth of HepG2 and SK-Hep-1 cells in response to adenine. Conclusions: These findings reveal that adenine reduces the cell growth of HepG2 and SK-Hep-1 but not Hep3B cells, attributing to the AMPK/p53-mediated S phase arrest and apoptosis. It suggests that adenine has anticancer potential against p53-wild type HCC cells and may be beneficial as an adjuvant for HCC treatment.

Effect of cholestasis and NeuroAid treatment on the expression of Bax, Bcl-2, Pgc-1α and Tfam genes involved in apoptosis and mitochondrial biogenesis in the striatum of male rats

Cholestasis means impaired bile synthesis or secretion. In fact, it is a bile flow reduction following Bile Duct Ligation (BDL). Cholestasis has a main role in necrosis and apoptosis. Apoptosis is a form of programmed cell death that has intrinsic and extrinsic pathways. The intrinsic pathway is mediated by Bcl-2 (B cell lymphoma-2) proteins which integrate death and survival signals. Bcl-2 has anti-apoptotic and Bax has pro-apoptotic effects. Also, striatum is one of the brain regions that has high expressions of Bcl-2 proteins. Moreover, Tfam and Pgc-1α are involved in mitochondrial biogenesis. On the other hand, NeuroAid, is a drug that has neuroprotective and anti-apoptosis effects. In this study, using quantitative PCR, we measured the expression of all these genes in the striatum of male rats following BDL and NeuroAid administration. Results showed, BDL increased the expression of Bax and Tfam and decreased the expression of Bcl-2. NeuroAid restored the effect of BDL on the expression of Bax, while did not alter the effect of BDL on Bcl-2. In addition, it increased the expression of Tfam that was previously elevated by BDL and raised the expression of Tfam in normal rats. Both BDL and NeuroAid, had no effect on Pgc-1α. In conclusion, cholestasis increased the expression of Bax and decreased the expression of Bcl-2, and this effect may have related to enhanced susceptibility of mitochondrial pathways following oxidative stress. Tfam expression was increased following cholestasis and this effect may have related to cellular compensatory mechanisms against high accumulation of free radicals or mitochondrial biogenesis failure. Furthermore, NeuroAid may play a role against apoptosis and can be used to increase mitochondrial biogenesis.

Nuciferine Prevents Hepatic Steatosis by Regulating Lipid Metabolismin Diabetic Rat Model

Objective

This study investigatesthe nuciferine capacity to regulate the liver’s lipid metabolism regarding steatosis and injury in STZ-induced diabetic rats.

Materials and Methods

The rats were randomly divided into groups control, diabetic and nuciferine 200 mg/kg/ day treatment. After 4 days of STZ injection, the nuciferine group was treated and administered via oral gavages for 4 weeks. At the end of experiment, blood, liver, myocardial and muscular samples were collected.

Results

Nuciferine-treated significantly increased the body weight from 339.4g to 367.8g, but significantly decreased the food and water intake compared with diabetic rats. Also, the nuciferine-treated rats had significantly decreased TC, TG, and FFAs in the liver compared with the diabetic group, especially the serum markers of blood glucose. These were associated with the gene expression related to lipogenesis which was significantly down-regulated; the gene expression involved in lipolysis and fatty acid β-oxidation was significantly up-regulated. Discussion and

Conclusion

The data provide evidence that nuciferine supplementation could protect the liver by regulating lipid metabolism gene expression resulting in decreasing the steatosis and injury in diabetic rat. Thus, nuciferine could be developed as a diabetic adjuvant food additive in future.

A Novel Indolizine Derivative Induces Apoptosis Through the Mitochondria p53 Pathway in HepG2 Cells

Indolizine derivatives are a class of compounds with excellent biological activity. In this study, a series of indolizine derivatives, compound 1 (C1), compound 2 (C2), compound 3 (C3), and compound 4 (C4), were synthesized. 3-(4,5-dimethylthiazole)-2,5-diphenyltetraazolium bromide (MTT) assay was used to evaluate their cytotoxicity against HepG2 (p53-wild), A549, and HeLa cell lines. HepG2 cells apoptosis induced by C3 was determined using Hoechst staining and acridine orange/ethidium bromide staining. Cells’ apoptotic ratio was measured by Annexin V–FITC/PI double staining. Changes in mitochondrial membrane potential and intracellular reactive oxygen species (ROS) in HepG2 cells after C3 treatment were determined. Immunofluorescence staining and Western blot analysis were carried out to detect p53 levels and analyze the apoptosis-associated proteins, respectively. Moreover, the cytotoxic activity of C3 was examined in two other hepatocellular carcinoma (HCC) cell lines with different p53 status including Huh-7 cells (p53-mutant) and Hep3B cells (p53-null). The results indicated that C3 showed stronger inhibition towards HepG2 cells than other cell lines. Fluorescent staining and flow cytometry analysis confirmed that C3 induced apoptosis of HepG2 cells. C3 could also increase intracellular ROS and cause a decrease in the mitochondrial membrane potential. C3 promoted p53 activation and increased p53 accumulation in nuclei. The expression of p53 and Bax was increased with the down-regulation of Bcl-2, which promoted the release of cytochrome c and caspase-3 activation. Collectively, the study demonstrated that C3 caused HepG2 cell apoptosis via the mitochondria p53 pathway. These results inspired us to further develop indolizine derivatives as potential potent inhibitors against liver cancer.

Long Noncoding RNA LL35/Falcor Regulates Expression of Transcription Factor Foxa2 in Hepatocytes in Normal and Fibrotic Mouse Liver

Long noncoding RNAs (lncRNA) play important roles in the regulation of transcription, splicing, translation, and other processes in the cell. Human and mouse lncRNA (DEANR1 and LL35/Falcor, respectively) located in the genomic environment in close proximity to the Foxa2 transcription factor were discovered earlier. In this work, tissue-specific expression of LL35/Falcor lncRNA has been shown in mouse liver and lungs. The use of antisense oligonucleotides allowed us to achieve LL35/Falcor lncRNA downregulation by 90%. As a result, the level of Foxa2 mRNA and protein dropped, which confirms the involvement of LL35/Falcor lncRNA in the regulation of transcription factor Foxa2. We have shown a decrease in the expression of LL35 lncRNA in liver fibrosis, which correlates with the previously published data for mRNA Foxa2. Thus, lncRNA LL35 regulates Foxa2 expression in the liver not only in normal conditions, but also during development of fibrosis, which allows one to consider lncRNA a biomarker of this pathological process.

Simvastatin Inhibits Endotoxin-Induced Apoptosis in Liver and Spleen Through Up-Regulation of Survivin/NF-κB/p65 Expression

Endotoxemia is associated by dysregulated apoptosis of immune and non-immune cells. We investigated whether simvastatin has anti-apoptotic effects, and induces hepatocytes and lymphocytes survival signaling in endotoxin-induced liver and spleen injuries. Wistar rats were divided into the groups pretreated with simvastatin (20 or 40 mg/kg, orally) prior to a non-lethal dose of lipopolysaccharide (LPS), the LPS group, and the control. The severity of tissue inflammatory injuries was expressed as hepatic damage scores (HDS) and spleen damage scores (SDS), respectively. The apoptotic cell was detected by TUNEL (Terminal deoxynucleotidyl transferase dUTP Nick End Labeling) and immunohistochemical staining (expression of cleaved caspase-3, and anti-apoptotic Bcl-xL, survivin and NF-κB/p65). Simvastatin dose-dependently abolished HDS and SDS induced by LPS (p < 0.01), respectively. Simvastatin 40 mg/kg significantly decreased apoptotic index and caspase-3 cleavage in hepatocytes and lymphocytes (p < 0.01 vs. LPS group, respectively), while Bcl-XL markedly increased accordingly with simvastatin doses. In the simvastatin, groups were determined markedly increased cytoplasmic expression of survivin associated with nuclear positivity of NF-κB, in both hepatocytes and lymphocytes (p < 0.01 vs. LPS group). Cell-protective effects of simvastatin against LPS seemed to be mediated by up-regulation of survivin, which leads to reduced caspase-3 activation and inhibition of hepatocytes and lymphocytes apoptosis.

Human skeletal muscle macrophages increase following cycle training and are associated with adaptations that may facilitate growth

Skeletal muscle macrophages participate in repair and regeneration following injury. However, their role in physiological adaptations to exercise is unexplored. We determined whether endurance exercise training (EET) alters macrophage content and characteristics in response to resistance exercise (RE), and whether macrophages are associated with other exercise adaptations. Subjects provided vastus lateralis biopsies before and after one bout of RE, after 12 weeks of EET (cycling), and after a final bout of RE. M2 macrophages (CD11b+/CD206+) did not increase with RE, but increased in response to EET (P < 0.01). Increases in M2 macrophages were positively correlated with fiber hypertrophy (r = 0.49) and satellite cells (r = 0.47). M2c macrophages (CD206+/CD163+) also increased following EET (P < 0.001), and were associated with fiber hypertrophy (r = 0.64). Gene expression was quantified using NanoString. Following EET, the change in M2 macrophages was positively associated with changes in HGF, IGF1, and extracellular matrix genes. EET decreased expression of IL6 (P < 0.05), C/EBPβ (P < 0.01), and MuRF (P < 0.05), and increased expression of IL-4 (P < 0.01), TNFα (P < 0.01) and the TWEAK receptor FN14 (P < 0.05). The change in FN14 gene expression was inversely associated with changes in C/EBPβ (r = -0.58) and MuRF (r = -0.46) following EET. In cultured human myotubes, siRNA inhibition of FN14 increased expression of C/EBPβ (P < 0.05) and MuRF (P < 0.05). Our data suggest that macrophages contribute to the muscle response to EET, potentially including modulation of TWEAK-FN14 signaling.

Protective Effects of Costunolide Against D-Galactosamine and Lipopolysaccharide-Induced Acute Liver Injury in Mice

Costunolide, a sesquiterpene isolated from Vladimiria souliei (Franch.) Ling, is known to exhibit anti-inflammatory, anti-viral, and anti-tumor activities. However, the effects of costunolide on liver injury are poorly understood. The current study aimed to investigate the hepatoprotective effects of costunolide against lipopolysaccharide (LPS) and D-galactosamine-induced acute liver injury (ALI) in mice. The results indicated that costunolide (40 mg/kg) could significantly improve the pathological changes of hepatic tissue, and reduced the LPS and D-galactosamine-induced increases of alanine aminotransferase (from 887.24 ± 21.72 to 121.67 ± 6.56 IU/L) and aspartate aminotransferase (from 891.01 ± 45.24 to 199.94 ± 11.53 IU/L) activities in serum. Further research indicated that costunolide significantly reduced malondialdehyde content (from 24.56 ± 1.39 to 9.17 ± 0.25 nmol/ml) and reactive oxygen species (from 203.34 ± 7.68 to 144.23 ± 7.12%), increased the activity of anti-oxidant enzymes superoxide dismutase (from 153.74 ± 10.33 to 262.27 ± 8.39 U/ml), catalase (from 6.12 ± 0.30 to 12.44 ± 0.57 U/ml), and total anti-oxidant capacity (from 0.64 ± 0.06 to 6.29 ± 0.11 U/ml) in hepatic tissues. Western blot results revealed that costunolide may trigger the anti-oxidative defense system by inhibiting kelch-like ECH-associated protein 1 and nuclear factor-related factor 2 (cytosol), increasing nuclear factor-related factor 2 (nucleus), heme oxygenase-1 and NAD (P) H quinone oxidoreductase 1 activity. Moreover, costunolide significantly decreased the protein expression of proinflammatory cytokines including interleukin 1β, interleukin 6, and tumor necrosis factor. Pretreatment with costunolide could reduce the expression of toll-like receptor 4, myeloid differentiation factor 88, p65 (Nucleus), phosphorylated IκB kinase α/β, inhibitor of nuclear factor kappa-B kinase, inhibitor kappa Bα and prevent the expression of phosphorylated inhibitor kappa B kinase which repressed translocation of p65 from cytoplasm to nucleus. In addition, pretreatment with costunolide also inhibited hepatocyte apoptosis by reducing the expression of B-cell lymphoma 2 associated X, cytochrome C, cysteinyl aspartate specific proteinase 3, cysteinyl aspartate specific proteinase 8 and cysteinyl aspartate specific proteinase 9, and by increasing B-cell lymphoma 2. From the above analysis, the protective effects of costunolide against LPS and D-galactosamine-induced ALI in mice may be attributed to its anti-oxidative activity in nuclear factor-related factor 2 signaling pathways, anti-inflammatory suppression in nuclear factor-kappa B signaling pathways, and inhibition of hepatocyte apoptosis. Thus, costunolide may be a potential therapeutic agent in attenuating LPS and D-galactosamine -induced ALI in the future.

3-Aminobenzamide Prevents Concanavalin A-Induced Acute Hepatitis by an Anti-inflammatory and Anti-oxidative Mechanism

BACKGROUND AND AIMS

Concanavalin A is known to activate T cells and to cause liver injury and hepatitis, mediated in part by secretion of TNFα from macrophages. Poly(ADP-ribose) polymerase-1 (PARP-1) inhibitors have been shown to prevent tissue damage in various animal models of inflammation. The objectives of this study were to evaluate the efficacy and mechanism of the PARP-1 inhibitor 3-aminobenzamide (3-AB) in preventing concanavalin A-induced liver damage.

METHODS

We tested the in vivo effects of 3-AB on concanavalin A-treated mice, its effects on lipopolysaccharide (LPS)-stimulated macrophages in culture, and its ability to act as a scavenger in in vitro assays.

RESULTS

3-AB markedly reduced inflammation, oxidative stress, and liver tissue damage in concanavalin A-treated mice. In LPS-stimulated RAW264.7 macrophages, 3-AB inhibited NFκB transcriptional activity and subsequent expression of TNFα and iNOS and blocked NO production. In vitro, 3-AB acted as a hydrogen peroxide scavenger. The ROS scavenger N-acetylcysteine (NAC) and the ROS formation inhibitor diphenyleneiodonium (DPI) also inhibited TNFα expression in stimulated macrophages, but unlike 3-AB, NAC and DPI were unable to abolish NFκB activity. PARP-1 knockout failed to affect NFκB and TNFα suppression by 3-AB in stimulated macrophages.

CONCLUSIONS

Our results suggest that 3-AB has a therapeutic effect on concanavalin A-induced liver injury by inhibiting expression of the key pro-inflammatory cytokine TNFα, via PARP-1-independent NFκB suppression and via an NFκB-independent anti-oxidative mechanism.

Effect of Puerarin Regulated mTOR Signaling Pathway in Experimental Liver Injury

It is known that excessive hepatocellular apoptosis is a typical characteristic of hepatic disease, and is regulated by the mammalian target of rapamycin (mTOR) signaling pathway. As the main active component of Kudzu (Pueraria lobata) roots, which is frequently used to treat hepatic diseases, Puerarin (Pue) has been reported to alleviate and protect against hepatic injury. However, it is unclear whether Pue can inhibit mTOR signaling to prevent excessive apoptosis in the treatment of hepatic diseases. In the present study, Pue effectively ameliorated pathological injury of the liver, decreased serum enzyme (ALT, AST, γ-GT, AKP, DBIL, and TBIL) levels, regulated the balance between pro-inflammatory (TNF-α, IL-1β, IL-4, IL-6, and TGF-β1) and anti-inflammatory cytokines (IL-10), restored the cell cycle and inhibited hepatocellular apoptosis and caspase-3 expression in rats with liver injury induced by 2-AAF/PH. Pue inhibited p-mTOR, p-AKT and Raptor activity, and increased Rictor expression in the liver tissues of rats with experimental liver injury. These results indicated that Pue effectively regulated the activation of mTOR signaling pathway in the therapeutic and prophylactic process of Pue on experimental liver injury.

Erzhi Pill® Protected Experimental Liver Injury Against Apoptosis via the PI3K/Akt/Raptor/Rictor Pathway

Erzhi Pill (EZP) is one of the basic prescriptions for treating liver diseases in traditional Chinese medicine. However, its mechanism of action is still undefined. The PI3K/AKT/Raptor/Rictor signaling pathway is closely related to apoptosis and plays a significant role in the pathogenesis of liver disease. To define the mechanism of the hepatoprotective effect of EZP in the treatment of liver disease, hepatic injury induced by 2-acetylaminofluorene/partial hepatectomy was treated by EZP for 14 days. The therapeutic effect of EZP was confirmed by the decreased production of aspartate aminotransferase and alanine aminotransferase, recovery of pathological liver injury, followed by inhibition of pro-inflammatory cytokines and transforming growth factor-β1. Bromodeoxyuridine assay and TUNEL staining indicated that apoptosis was suppressed and the numbers of cells in S phase and G0/G1phase were decreased. The crucial proteins in the PI3K/AKT/Raptor/Rictor signaling pathway were deactivated in rats with experimental liver injury treated by EZP. These results indicated that the hepatoprotective effect of EZP via inhibition of hepatocyte apoptosis was closely related to repression of the PI3K/Akt/Raptor/Rictor signaling pathway.

Curcumin attenuates oxidative stress in liver in Type 1 diabetic rats

We investigated the effect of curcumin on liver anti-oxidative stress in the type 1 diabetic rat model induced by streptozotocin (STZ). Experimental diabetic rats were induced by STZ intraperitoneally. All rats were fed for 21 days including three groups of control (NC), diabetic model (DC) and curcumin-treated (Cur, 1.5 g/kg by gavage). The results showed that curcumin-treatment significantly decreased the blood glucose and plasma malondialdehyde levels, but significantly increased the plasma superoxide dismutase, glutathione peroxidase and reduced glutathione levels. Curcumin treatment decreased the activity of aldose reductase, but increased the plasma glucose-6-phosphate dehydrogenase, glucose synthetase and glucose-polymerizing activities. Curcumin treatment significantly decreased the protein of protein kinase C (PKC) and poly ADP ribose polymerase (PARP) expression in the Cur group compared with the DC group. Moreover, the sorbitol dehydrogenase activity was significantly decreased and deterred glucose enters into the polyol pathway leading to an increased NADPH content in the Cur group compared with the DC group. Our data provides evidence that oxidative stress in diabetic rats may be attenuated by curcumin by inhibiting polyol pathway associated with down-regulated expression of PKC and PARP, as evidenced by both an increase the antioxidant enzymes levels and glycogen biosynthesis enzymes activities.

FOXA2 alleviates CCl4-induced liver fibrosis by protecting hepatocytes in mice

The liver-enriched transcription factor Forkhead Box A2 (FOXA2) has been reported to be involved in bile acid homeostasis and bile duct development. However, the role of FOXA2 in liver fibrogenesis remains undefined. In this study, we found that the abundance of FOXA2 was significantly lower in fibrotic livers of patients and mice treated with CCl₄ than in controls. Interestingly, the expression level of FOXA2 decreased in hepatocytes, whereas FOXA2 was elevated in hepatic stellate cells (HSCs) of mouse fibrotic livers. Hepatocyte-specific ablation of FOXA2 in adult mice exacerbated liver fibrosis induced by CCl₄. Either lentivirus LV-CMV-FOXA2 mediated FOXA2 overexpression in the liver or adeno-associated virus AAV8-TBG-FOXA2-mediated hepatocyte-specific upregulation of FOXA2 alleviated hepatic fibrosis. Overexpression of FOXA2 in HSCs did not obviously affect hepatic fibrogenesis. Additionally, FOXA2 knockout in hepatocytes resulted in aberrant transcription of metabolic genes. Furthermore, hepatocyte-specific knockout of FOXA2 enhanced endoplasmic reticulum stress (ER stress) and the apoptosis of hepatocytes, whereas FOXA2 overexpression in hepatocytes suppressed ER stress and hepatocyte apoptosis in mouse fibrotic livers. In conclusion, our findings suggested that FOXA2-mediated hepatocyte protection has a therapeutic role in hepatic fibrosis, and thus may be a new, promising anti-fibrotic option for treating chronic liver diseases.

Curcumin alleviates liver oxidative stress in type 1 diabetic rats

The aim of the present study was to determine the effects of curcumin on antioxidants using a rat model of type 1 diabetes. Seven-week-old male Sprague-Dawley rats were injected with Streptozotocin (STZ) intraperitoneally to induce this model, and then treated with 1.0% curcumin (weight ratio) mixed in their diet for 21 days. The present study included three groups: Control group (NC), diabetic rat model group (DC) and a curcumin treated group (Diab-Cur). The results demonstrated that curcumin treatment markedly decreased the blood glucose levels, plasma malondialdehyde concentration and plasma activity of glutathione peroxidase (GSH-Px) and catalase (CAT); however, it increased the plasma superoxide dismutase (SOD) and insulin levels. Curcumin treatment increased the expression of the CAT, GSH-Px, HO-1 and norvegicus NAD(P)H quinone dehydrogenase 1, and decreased the SOD1 expression, which, led to a diminished oxidative stress status. In addition, curcumin treatment significantly increased the protein expression of Keap1 in the Diab-Cur group when compared with the DC group, decreased cytosolic concentrations of Nrf2 while increasing nuclear accumulation of Nrf2. The results provide evidence that oxidative stress in the STZ-induced diabetic rat model may be attenuated by curcumin via the activation of the Keap1-Nrf2-ARE signaling pathway, as evidenced by a decrease in the blood glucose concentration and an increase in the transcription of several antioxidant genes.

Erzhi Pill® Repairs Experimental Liver Injury via TSC/mTOR Signaling Pathway Inhibiting Excessive Apoptosis

The present study aimed to investigate the mechanism of hepatoprotective effect of Erzhi Pill (EZP) on the liver injury via observing TSC/mTOR signaling pathway activation. The experimental liver injury was induced by 2-acetylaminofluorene (2-AAF) treatment combined with partial hepatectomy (PH). EZP treated 2-AAF/PH-induced liver injury by the therapeutic and prophylactic administration. After the administration of EZP, the activities of aspartic transaminase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AKP), and gamma-glutamyl transpeptidase (γ-GT) were decreased, followed by the decreased levels of hepatocyte apoptosis and caspase-3 expression. However, the secretion of albumin, liver weight, and index of liver weight were elevated. Microscopic examination showed that EZP restored pathological liver injury. Meanwhile, Rheb and mammalian target of rapamycin (mTOR) activation were suppressed, and tuberous sclerosis complex (TSC) expression was elevated in liver tissues induced by 2-AAF/PHx and accompanied with lower-expression of Bax, Notch1, p70S6K, and 4E-EIF and upregulated levels of Bcl-2 and Cyclin D. Hepatoprotective effect of EZP was possibly realized via inhibiting TSC/mTOR signaling pathway to suppress excessive apoptosis of hepatocyte.

Mechanisms and treatment of liver fibrosis

Hepatic fibrosis is a characteristic consequence of multiple chronic liver injuries. However, there are currently no specific drugs that can effectively reverse or prevent liver fibrosis progression. Liver fibrosis is a complex pathological process attributable to a variety of cytokines and molecular pathways. Therefore, further exploring the cellular and molecular mechanisms of liver fibrosis, unearthing specific anti-fibrosis targeted therapies and translation of the potential findings into clinical treatment are of great significance.

Nuclear translocation of nuclear factor kappa B is regulated by G protein signaling pathway in arsenite-induced apoptosis in HBE cell line

Arsenite is a certainly apoptosis inducer in various cell types. However, the detailed mechanism underlying how arsenite trigger apoptosis remains elusive. In this study, using human bronchial epithelial cell as a culture system, we demonstrated that arsenite-induced nuclear translocation of nuclear factor kappa B (NF-κB) resulted in the release of cytochrome c, the modulation of Fas and FasL, caspase activation, and ultimately leading to cell apoptosis. Importantly, we showed for the first time that the NF-κB-mediated apoptosis induced by arsenite was regulated by G protein-adenylate cyclase (AC)-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway. Inhibition of this classical G protein signaling pathway by a typical PKA inhibitor, H-89, caused the inactivation of NF-κB, the depletion of caspase-3, 8 and 9 activities, and thus reducing the level of cell apoptosis. Taken together, our results indicate that arsenite is able to trigger cell apoptosis in human bronchial epithelial cells through the nuclear translocation of NF-κB, which can be modulated by G protein signaling pathway. These findings further suggest that inhibition of G protein-mediated pathway by specific inhibitors may be a potential strategy for the prevention of arsenite toxicity. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1819-1833, 2016.

Effects of Myrtus communis extract treatment in bile duct ligated rats

BACKGROUND

The aim of our study was to investigate the antifibrotic and antioxidant effects of Myrtus communis subsp. communis (MC) extract against liver injury and fibrosis occurring in rats with biliary obstruction.

MATERIALS AND METHODS

The rats were randomized into four groups (n = 8). Control group (C), MC-administrated group (MC), the bile duct ligation (BDL), and BDL + MC groups. MC was administered at a dose of 50 mg/kg a day orally for 28 days. In blood samples, total bilirubin, direct bilirubin, alanine aminotransferase, aspartate aminotransferase levels, tumor necrosis factor-α, and interleukin-1β measurement were measured. Oxidative injury was examined by measuring luminol and lucigenin chemiluminescence, malondialdehyde and glutathione levels, superoxide dismutase and myeloperoxidase activities. Transforming growth factor-beta and hydroxyproline levels were measured for analyzing fibrosis. The hepatic injury was also analyzed microscopically.

RESULTS

Plasma total bilirubin, direct bilirubin, alanine aminotransferase, aspartate aminotransferase, tumor necrosis factor-α, and interleukin-1β levels were found significantly high in the BDL group, while these values significantly decreased in the BDL group treated with MC. On the other hand, the glutathione and superoxide dismutase values significantly decreased in the BDL group compared to the control group but increased markedly in BDL + MC group compared to the BDL group. Malondialdehyde levels, myeloperoxidase activity, tissue luminol, lucigenin, transforming growth factor-beta, and hydroxyproline levels when compared with the control group increased dramatically in the BDL group and reduced the MC + BDL group.

CONCLUSIONS

Our results suggest that MC protects the liver tissues against oxidative damage following BDL via its radical scavenging and antioxidant activities, which appear to involve the inhibition of tissue neutrophil infiltration.

Prevention and Therapeutic Effects and Mechanisms of Tanshinone IIA Sodium Sulfonate on Acute Liver Injury Mice Model

Tanshinone IIA sodium sulfonate (TSS) is a water-soluble derivative of tanshinone IIA, which is the main pharmacologically active component of Salvia miltiorrhiza. This study aimed to verify the preventive and therapeutic effects of TSS and its combined therapeutic effects with magnesium isoglycyrrhizinate (MI) in D-galactosamine- (D-Gal-) induced acute liver injury (ALI) in mice. The potential regulatory mechanisms of TSS on ALI were also examined. Our results may provide a basis for the development of novel therapeutics for ALI.

CdSe/ZnS quantum dots induce photodynamic effects and cytotoxicity in pancreatic cancer cells

AIM: To investigate the photodynamic effect of CdSe/ZnS quantum dots (QDs) on pancreatic cancer cells and elucidate the probable mechanisms.

METHODS: The pancreatic cancer cell line SW1990 was treated with different concentrations of CdSe/ZnS QDs (0, 0.5, 1.0, 1.5, 2.0, 2.5 μmol/L), with or without illumination. The viability of SW1990 cells was tested using the Cell Counting Kit-8 (CCK-8) assay. The ultrastructural changes of SW1990 cells were observed by transmission electron microscopy. Apoptosis was detected by nuclear staining and flow cytometry (FCM). Reactive oxygen species (ROS) were measured by dichlorofluorescein diacetate via fluorescence microscopy. Expression of Bax, Bcl-2 and caspase-3 was measured by real-time polymerase chain reaction (PCR) and protein immunoblotting 24 h after SW1990 cells were treated with CdSe/ZnS QDs and illuminated.

RESULTS: The CCK-8 assay results showed that both CdSe/ZnS QDs with and without illumination suppressed SW1990 cell proliferation. Cell viability was significantly lower when illuminated or with a longer incubation time and a higher light dose. CdSe/ZnS QDs with illumination caused ultrastructural changes in SW1990 cells, such as organelle degeneration and chromatin condensation and aggregation at the periphery of the nucleus. Fluorescence microscopy and FCM showed that CdSe/ZnS QDs (1.5 μmol/L) with illumination increased SW1990 cell apoptosis (53.2%) and ROS generation compared with no illumination. Real-time PCR showed that expression of Bax and caspase-3 was upregulated and Bcl-2 was downregulated. Immunoblotting results were consistent with real-time PCR results. Inhibition of ROS and apoptosis both attenuated QD-photodynamic-therapy-induced cell death.

CONCLUSION: CdSe/ZnS QDs can be used as a photosensitizer to inhibit SW1990 cell proliferation through ROS generation and apoptotic protein expression regulation.

Prediction of tissue-specific effects of gene knockout on apoptosis in different anatomical structures of human brain

BACKGROUND

An important issue in the target identification for the drug design is the tissue-specific effect of inhibition of target genes. The task of assessing the tissue-specific effect in suppressing gene activity is especially relevant in the studies of the brain, because a significant variability in gene expression levels among different areas of the brain was well documented.

RESULTS

A method is proposed for constructing statistical models to predict the potential effect of the knockout of target genes on the expression of genes involved in the regulation of apoptosis in various brain regions. The model connects the expression of the objective group of genes with expression of the target gene by means of machine learning models trained on available expression data. Information about the interactions between target and objective genes is determined by reconstruction of target-centric gene network. STRING and ANDSystem databases are used for the reconstruction of gene networks. The developed models have been used to analyse gene knockout effects of more than 7,500 target genes on the expression of 1,900 objective genes associated with the Gene Ontology category "apoptotic process". The tissue-specific effect was calculated for 12 main anatomical structures of the human brain. Initial values of gene expression in these anatomical structures were taken from the Allen Brain Atlas database. The results of the predictions of the effect of suppressing the activity of target genes on apoptosis, calculated on average for all brain structures, were in good agreement with experimental data on siRNA-inhibition.

CONCLUSIONS

This theoretical paper presents an approach that can be used to assess tissue-specific gene knockout effect on gene expression of the studied biological process in various structures of the brain. Genes that, according to the predictions of the model, have the highest values of tissue-specific effects on the apoptosis network can be considered as potential pharmacological targets for the development of drugs that would potentially have strong effect on the specific area of the brain and a much weaker effect on other brain structures. Further experiments should be provided in order to confirm the potential findings of the method.

Expression pattern and transcriptional regulatory mechanism of noxa gene in grass carp (Ctenopharyngodon idella)

Noxa, a pro-apoptotic protein, plays an important role in cell apoptosis. The researches about noxa gene were concentrated in mammalians, whereas the role and transcriptional regulatory mechanism of noxa in fish were still unclear. In this study, the expression pattern and transcriptional regulatory mechanism of noxa gene in grass carp were analyzed. Noxa was constitutively expressed in all the examined tissues but the relative expression level differed. After exposure to grass carp reovirus (GCRV), mRNA expression level of noxa was down-regulated at the early phase whereas up-regulated at the late phase of infection. Luciferase assays showed that the promoter region -867 ∼ +107 of noxa had high activity and the region -678 ∼ -603 was important in the response to GCRV infection. By deleting the predicted transcription factor binding sites, transcription factors FOXO1 and CEBPβ were found important for noxa in response to GCRV infection. Moreover, the noxa promoter was biotin-labeled and incubated with nuclear extracts from GCRV infected cells. Mass spectrometry analysis showed that transcription factors FOXO1 and CEBPβ were also enriched in the combined proteins. Therefore, the results suggested that transcription factors FOXO1 and CEBPβ may play an important role in the regulation of noxa. Our study would provide new insight into the transcriptional regulatory mechanism of noxa in teleost fish.

Proinflammatory mesenchymal effects of the non-genotoxic hepatocarcinogen phenobarbital: a novel mechanism of antiapoptosis and tumor promotion

Many environmental pollutants and drugs, including steroid hormones, hypolipidemics and antiepileptics, are non-genotoxic carcinogens (NGC) in rodent liver. The mechanism of action and the risk for human health are still insufficiently known. Here, we study the effects of phenobarbital (PB), a widely used model NGC, on hepatic epithelial-mesenchymal crosstalk and the impact on hepatic apoptosis. Mesenchymal cells (MC) and hepatocytes (HC) were isolated from control and PB-treated rat livers. PB induced extensive changes in gene expression in MC and much less in HC as shown by transcriptomics with oligoarrays. In MC only, transcript levels of numerous proinflammatory cytokines were elevated. Correspondingly, ELISA on the supernatant of MC from PB-treated rats revealed enhanced release of various cytokines. In cultured HC, this supernatant caused (i) nuclear translocation and activation of nuclear factor-κB (shown by immunoblots of nuclear extracts and reporter gene assays), (ii) elevated expression of proinflammatory genes and (iii) protection from the proapoptotic action of transforming growth factor beta 1 (TGFß1). PB treatment in vivo or in vitro elevated the production and release of tumor necrosis factor alpha from MC, which was identified as mainly responsible for the inhibition of apoptosis in HC. In conclusion, our findings reveal profound proinflammatory effects of PB on hepatic mesenchyme and mesenchymal-epithelial interactions. The resulting release of cytokines acts antiapoptotic in HC, an effect crucial for tumor promotion and carcinogenesis by NGC.