Background and aims: The monosaccharide mannose has gained recent interest for its beneficial eff... more Background and aims: The monosaccharide mannose has gained recent interest for its beneficial effect against certain inflammatory disorders. Nevertheless, the influence of mannose on experimentally-induced liver fibrosis and the ensued inflammation is still not fully clear to date. Main methods: The current study investigated the outcomes of treating rats with mannose (0.2 ml of 20% w/v, oral gavage) 30 min before the twice weekly intoxication with thioacetamide (TAA) (200 mg/kg, intraperitoneal) for a total period of 8 weeks. Key findings: The data indicated that mannose markedly dampened TAA-induced liver fibrosis, as indicated by lowering the fibrotic bridges shown by Masson's trichrome staining. This effect was consistent with reducing TAA-induced hepatocellular injury, as evidenced biochemically (serum ALT and AST activities) and pathologically (necroinflammation score). These hepatoprotective effects mediated by mannose were attributed to i) reversing TAA-induced rise in malondialdehyde (MDA) and decrease in reduced glutathione (GSH) expressions in the liver, ii) limiting TAA-induced release of the proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), iii) impairing TAA-induced activation of hepatic stellate cells by downregulating α-smooth muscle actin expression (α-SMA), and more importantly, iv) dampening TAA-induced fibrogenesis driven by transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF). Significance: Mannose may be a valuable candidate for preventing oxidative stress, inflammation and fibrogenesis in the liver.
Bruton tyrosine kinase (BTK) sits at the crossroads of adaptive and innate immunities. Neverthele... more Bruton tyrosine kinase (BTK) sits at the crossroads of adaptive and innate immunities. Nevertheless, the detailed role of BTK activation in hepatic inflammatory disorders is still elusive to date. Accordingly, we investigated the impact of blocking BTK activation by acalabrutinib (ACB) on lipopolysaccharide/galactosamine (LPS/D-GaIN)induced deleterious manifestations in the liver. This was achieved by pretreating mice with ACB (6, 12 or 24 mg/ kg, oral) 2 h before challenge with LPS/D-GaIN (70 μg/kg and 700 mg/kg, respectively, i.p.) for 6 h. The results showed that ACB (6 and 12 mg/kg) (i) curbed LPS/D-GaIN-induced rise in biochemical (serum ALT, AST and LDH) and histological (necrosis, degeneration and congestion scores) indices of hepatocellular injury; (ii) attenuated LPS/D-GaIN-induced elevation in parameters of hepatocellular apoptosis (cleaved caspase 3) and proliferation (PCNA); and (iii) importantly, mitigated LPS/D-GaIN-induced recruitment and infiltration of the inflammatory cells to the liver evidenced by lowering elevated serum MCP-1 concentration and hepatic F4/80 immunostaining. These effects were linked to ACB dose-dependent inhibition of NF-κB nuclear translocation that subsequently reduced LPS/D-GaIN-mediated release of TNF-α, IL-1β and IL-22 in the blood circulation. However, a dose of 12 mg/kg of ACB elevated the hepatic TNF-α, IL-1β and IL-22 concentrations that arose from a compensatory activation of ERK and JNK. Inhibition of BTK also attenuated LPS/D-GaIN-induced overexpression of CD98, which is another contributor alongside cytokines for monocyte recruitment. Therapeutically, targeting BTK by ACB is an efficient approach for hitting multiple points with one agent that can dampen hepatocellular injury, death, immune cell recruitment and inflammation cascade.
Objectives: MLN4924 is an inhibitor of NEDD8-activating enzyme (NAE) that interferes with the cul... more Objectives: MLN4924 is an inhibitor of NEDD8-activating enzyme (NAE) that interferes with the cullin-RING ubiquitin ligase complexes formation and the nuclear factor kappa B (NF-κB) activation. Here, we investigated the cytotoxic effect of MLN4924 and its ability to sensitize a broad range of cancer cells of different origins to tumour necrosis factor-α (TNF)-induced cell death alongside unravelling its mechanism of action. Materials and methods: Cell viability and caspases processing were determined after MLN4924 treatment either alone or with zVAD-fmk (pan caspase inhibitor), necrostatin-1 (nec-1, RIPK1 inhibitor) and necrosulfonamide (NSA, MLKL inhibitor). Moreover, MLN4924 ability to potentiate TNF-induced cell death was evaluated in 24 cell lines of different cancer origins. The impact of NAE inhibition with MLN4924 on TNF-induced apoptosis and necroptosis was evaluated using zVAD-fmk and nec-1, respectively. Results: MLN4924 alone was able to induce cell death in different cell lines that was attributed to apoptosis induction. Also, MLN4924 sensitized different cancer cell lines to TNF-induced cell death. MLN4924/TNFinduced cell death was apoptosis and necroptosis dependent that may be attributed to MLN4924 inhibition of NF-κB pathway activation. Conclusions: Targeting NAE and NF-κB pathway with MLN4924 represents a substantial approach to enhance the sensitivity of diverse types of cancer cells. Moreover, the broad in vitro screening of MLN4924 anticancer activity provides a valuable guidance for elucidating the susceptible cancer types for the prospective clinical application of MLN4924.
The incorporation of mesenchymal-epithelial transition factor (c-Met) inhibitors with conventiona... more The incorporation of mesenchymal-epithelial transition factor (c-Met) inhibitors with conventional chemotherapeutics may increase the anticancer efficacy of chemotherapeutic agents, but bears the risk of enhancing the adverse effects. To test the hypothesis, co-administration of the novel c-Met inhibitor capmatinib with cisplatin (CIS) or doxorubicin (DOX) was investigated on nephrotoxicity and cardiotoxicity induced by these agents in mice, as well as their in vitro cytotoxicities. The results demonstrated that capmatinib in vivo offered protection against nephrotoxicity and cardiotoxicity by both CIS and DOX, respectively. The underlying mechanisms behind capmatinib protective effect were found to be i) limiting excessive generation of reactive oxygen species by decreasing the level of lipid peroxidation and nitrosative stress products; and ii) suppressing overproduction of pro-inflammatory mediators like TNF-α and IL-6 that coincided with less inflammatory cell infiltration as denoted by lower levels of serum MCP-1 and Ly6G immunostaining. Besides, capmatinib effectively improved the in vivo anticancer efficacy of both CIS and DOX against solid tumors. In vitro, capmatinib increased the apoptotic activity of DOX against cancerous cells, but did not affect that of CIS. This effect might be linked to capmatinib and DOX abilities to lower IL-12(p40) that has an inhibitory effect on IL-12(p70)/IFN-γ-mediated apoptotic activity. In conclusion, the favorable effects of capmatinib can be applied clinically to decrease the toxicity of DOX and CIS chemotherapeutic agents.
Acetaminophen (APAP)-induced hepatotoxicity comes among the most frequent humans' toxicities caus... more Acetaminophen (APAP)-induced hepatotoxicity comes among the most frequent humans' toxicities caused by drugs. So far, therapeutic interventions for such type of drug-induced toxicity are still limited. In the current study, we examined the influence of capmatinib (Cap), a novel c-Met inhibitor, on APAP-induced hepatotoxicity in mice when administered 2 h prior, 2 h post and 4 h post APAP-challenge. The results revealed that Cap administration significantly attenuated APAP-induced liver injury when administered only 2 h prior and post APAP-administration. Cap hepatoprotective effect was mediated by lowering the excessive formation of lipid peroxidation and nitrosative stress products caused by APAP. Besides, Cap attenuated APAP-induced overproduction and release of proinflammatory mediators like TNF-α, IL-1β, IL-17A, IL-6, and MCP-1. Cap treatment also led to avoidance of APAP-subsequent repair by abating APAP-induced elevation of hepatic IL-22 and PCNA expressions. In conclusion, c-Met receptor inhibition may be a potential strategy for alleviating APAP-hepatotoxicity, especially when administered in the early phase of intoxication.
Interleukins (ILs)-22, 32α and 34 were monitored in the sera of relapsing-remitting multiple scle... more Interleukins (ILs)-22, 32α and 34 were monitored in the sera of relapsing-remitting multiple sclerosis (RRMS) patients at different time intervals with or without interferon β-1b, interferon β-1a and fingolimod treatments. The results showed that sera of untreated RRMS patients were statistically higher in concentration of IL-22 (P < .001), but not IL-32α and IL-34, than those of healthy individuals. Interestingly, interferon β-1b, interferon β-1a and fingolimod treatments led to a significant decrease of serum concentrations of ILs-22 and 32α, but not 34, at 6 and 12 months of treatment, compared to their initial concentrations before initiating therapy. The correlation analysis revealed that the changes of serum IL-22 (r = 0.814) and, to a lesser extent, IL-32α (r = 0.381) concentrations were positively correlated with those of expanded disability status score. In conclusion, serum IL-22 concentration may be a potential marker for MS disease severity and efficacy of treatment.
The sterile inflammatory response is an eminent contributor to acetaminophen (APAP)-hepatotoxicit... more The sterile inflammatory response is an eminent contributor to acetaminophen (APAP)-hepatotoxicity in humans. Recent advances unraveled an axial role of the NLRP3-inflammasome in APAP-post injury inflammation. Nevertheless, the role of signaling events preceded the NLRP3-inflammasome activation, like the transcription factor NF-κB and the purinergic receptor P2X7, is still unclear and needs further elucidation. Here, we investigated the pharmacological inhibition of these upstream signaling molecules by celastrol and brilliant blue G (BBG) (separately or simultaneously) in APAP-hepatotoxicity in mice. The results indicated that both celastrol and BBG pretreatments, especially when combined together, curbed APAP-induced hepatocellular injury (ALT, AST and LDH) and death (necrosis and apoptosis). The underlying mechanisms of protection of such combination against APAP-challenge were attributed to their efficient cooperation in: i) preventing the consumption of hepatic antioxidants (reduced glutathione and superoxide dismutase); ii) limiting the overproduction of lipid peroxidation aldehydes (malondialdehyde and 4-hydroxynonenal) and total nitrate/nitrite products; iii) attenuating the inflammatory cells accumulation in the liver, as evidenced by reducing the number of F4/80 positive cells/field in immunostaining and myeloperoxidase activity; iv) reversing the dysregulation in production of pro-inflammatory (TNF-α, IL-17A and IL-23) and anti-inflammatory (IL-10) cytokines; and v) enhancing the reparative capacity of injured hepatocytes, as demonstrated by increasing the percentage of PCNA positive hepatocytes per field of immunostaining. In conclusion, this murine study elicits a potential clinical applicability and therapeutic utility of celastrol and BBG combination in human cases of APAP-overdose hepatotoxicity.
Background and aims: The monosaccharide mannose has gained recent interest for its beneficial eff... more Background and aims: The monosaccharide mannose has gained recent interest for its beneficial effect against certain inflammatory disorders. Nevertheless, the influence of mannose on experimentally-induced liver fibrosis and the ensued inflammation is still not fully clear to date. Main methods: The current study investigated the outcomes of treating rats with mannose (0.2 ml of 20% w/v, oral gavage) 30 min before the twice weekly intoxication with thioacetamide (TAA) (200 mg/kg, intraperitoneal) for a total period of 8 weeks. Key findings: The data indicated that mannose markedly dampened TAA-induced liver fibrosis, as indicated by lowering the fibrotic bridges shown by Masson's trichrome staining. This effect was consistent with reducing TAA-induced hepatocellular injury, as evidenced biochemically (serum ALT and AST activities) and pathologically (necroinflammation score). These hepatoprotective effects mediated by mannose were attributed to i) reversing TAA-induced rise in malondialdehyde (MDA) and decrease in reduced glutathione (GSH) expressions in the liver, ii) limiting TAA-induced release of the proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), iii) impairing TAA-induced activation of hepatic stellate cells by downregulating α-smooth muscle actin expression (α-SMA), and more importantly, iv) dampening TAA-induced fibrogenesis driven by transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF). Significance: Mannose may be a valuable candidate for preventing oxidative stress, inflammation and fibrogenesis in the liver.
Bruton tyrosine kinase (BTK) sits at the crossroads of adaptive and innate immunities. Neverthele... more Bruton tyrosine kinase (BTK) sits at the crossroads of adaptive and innate immunities. Nevertheless, the detailed role of BTK activation in hepatic inflammatory disorders is still elusive to date. Accordingly, we investigated the impact of blocking BTK activation by acalabrutinib (ACB) on lipopolysaccharide/galactosamine (LPS/D-GaIN)induced deleterious manifestations in the liver. This was achieved by pretreating mice with ACB (6, 12 or 24 mg/ kg, oral) 2 h before challenge with LPS/D-GaIN (70 μg/kg and 700 mg/kg, respectively, i.p.) for 6 h. The results showed that ACB (6 and 12 mg/kg) (i) curbed LPS/D-GaIN-induced rise in biochemical (serum ALT, AST and LDH) and histological (necrosis, degeneration and congestion scores) indices of hepatocellular injury; (ii) attenuated LPS/D-GaIN-induced elevation in parameters of hepatocellular apoptosis (cleaved caspase 3) and proliferation (PCNA); and (iii) importantly, mitigated LPS/D-GaIN-induced recruitment and infiltration of the inflammatory cells to the liver evidenced by lowering elevated serum MCP-1 concentration and hepatic F4/80 immunostaining. These effects were linked to ACB dose-dependent inhibition of NF-κB nuclear translocation that subsequently reduced LPS/D-GaIN-mediated release of TNF-α, IL-1β and IL-22 in the blood circulation. However, a dose of 12 mg/kg of ACB elevated the hepatic TNF-α, IL-1β and IL-22 concentrations that arose from a compensatory activation of ERK and JNK. Inhibition of BTK also attenuated LPS/D-GaIN-induced overexpression of CD98, which is another contributor alongside cytokines for monocyte recruitment. Therapeutically, targeting BTK by ACB is an efficient approach for hitting multiple points with one agent that can dampen hepatocellular injury, death, immune cell recruitment and inflammation cascade.
Objectives: MLN4924 is an inhibitor of NEDD8-activating enzyme (NAE) that interferes with the cul... more Objectives: MLN4924 is an inhibitor of NEDD8-activating enzyme (NAE) that interferes with the cullin-RING ubiquitin ligase complexes formation and the nuclear factor kappa B (NF-κB) activation. Here, we investigated the cytotoxic effect of MLN4924 and its ability to sensitize a broad range of cancer cells of different origins to tumour necrosis factor-α (TNF)-induced cell death alongside unravelling its mechanism of action. Materials and methods: Cell viability and caspases processing were determined after MLN4924 treatment either alone or with zVAD-fmk (pan caspase inhibitor), necrostatin-1 (nec-1, RIPK1 inhibitor) and necrosulfonamide (NSA, MLKL inhibitor). Moreover, MLN4924 ability to potentiate TNF-induced cell death was evaluated in 24 cell lines of different cancer origins. The impact of NAE inhibition with MLN4924 on TNF-induced apoptosis and necroptosis was evaluated using zVAD-fmk and nec-1, respectively. Results: MLN4924 alone was able to induce cell death in different cell lines that was attributed to apoptosis induction. Also, MLN4924 sensitized different cancer cell lines to TNF-induced cell death. MLN4924/TNFinduced cell death was apoptosis and necroptosis dependent that may be attributed to MLN4924 inhibition of NF-κB pathway activation. Conclusions: Targeting NAE and NF-κB pathway with MLN4924 represents a substantial approach to enhance the sensitivity of diverse types of cancer cells. Moreover, the broad in vitro screening of MLN4924 anticancer activity provides a valuable guidance for elucidating the susceptible cancer types for the prospective clinical application of MLN4924.
The incorporation of mesenchymal-epithelial transition factor (c-Met) inhibitors with conventiona... more The incorporation of mesenchymal-epithelial transition factor (c-Met) inhibitors with conventional chemotherapeutics may increase the anticancer efficacy of chemotherapeutic agents, but bears the risk of enhancing the adverse effects. To test the hypothesis, co-administration of the novel c-Met inhibitor capmatinib with cisplatin (CIS) or doxorubicin (DOX) was investigated on nephrotoxicity and cardiotoxicity induced by these agents in mice, as well as their in vitro cytotoxicities. The results demonstrated that capmatinib in vivo offered protection against nephrotoxicity and cardiotoxicity by both CIS and DOX, respectively. The underlying mechanisms behind capmatinib protective effect were found to be i) limiting excessive generation of reactive oxygen species by decreasing the level of lipid peroxidation and nitrosative stress products; and ii) suppressing overproduction of pro-inflammatory mediators like TNF-α and IL-6 that coincided with less inflammatory cell infiltration as denoted by lower levels of serum MCP-1 and Ly6G immunostaining. Besides, capmatinib effectively improved the in vivo anticancer efficacy of both CIS and DOX against solid tumors. In vitro, capmatinib increased the apoptotic activity of DOX against cancerous cells, but did not affect that of CIS. This effect might be linked to capmatinib and DOX abilities to lower IL-12(p40) that has an inhibitory effect on IL-12(p70)/IFN-γ-mediated apoptotic activity. In conclusion, the favorable effects of capmatinib can be applied clinically to decrease the toxicity of DOX and CIS chemotherapeutic agents.
Acetaminophen (APAP)-induced hepatotoxicity comes among the most frequent humans' toxicities caus... more Acetaminophen (APAP)-induced hepatotoxicity comes among the most frequent humans' toxicities caused by drugs. So far, therapeutic interventions for such type of drug-induced toxicity are still limited. In the current study, we examined the influence of capmatinib (Cap), a novel c-Met inhibitor, on APAP-induced hepatotoxicity in mice when administered 2 h prior, 2 h post and 4 h post APAP-challenge. The results revealed that Cap administration significantly attenuated APAP-induced liver injury when administered only 2 h prior and post APAP-administration. Cap hepatoprotective effect was mediated by lowering the excessive formation of lipid peroxidation and nitrosative stress products caused by APAP. Besides, Cap attenuated APAP-induced overproduction and release of proinflammatory mediators like TNF-α, IL-1β, IL-17A, IL-6, and MCP-1. Cap treatment also led to avoidance of APAP-subsequent repair by abating APAP-induced elevation of hepatic IL-22 and PCNA expressions. In conclusion, c-Met receptor inhibition may be a potential strategy for alleviating APAP-hepatotoxicity, especially when administered in the early phase of intoxication.
Interleukins (ILs)-22, 32α and 34 were monitored in the sera of relapsing-remitting multiple scle... more Interleukins (ILs)-22, 32α and 34 were monitored in the sera of relapsing-remitting multiple sclerosis (RRMS) patients at different time intervals with or without interferon β-1b, interferon β-1a and fingolimod treatments. The results showed that sera of untreated RRMS patients were statistically higher in concentration of IL-22 (P < .001), but not IL-32α and IL-34, than those of healthy individuals. Interestingly, interferon β-1b, interferon β-1a and fingolimod treatments led to a significant decrease of serum concentrations of ILs-22 and 32α, but not 34, at 6 and 12 months of treatment, compared to their initial concentrations before initiating therapy. The correlation analysis revealed that the changes of serum IL-22 (r = 0.814) and, to a lesser extent, IL-32α (r = 0.381) concentrations were positively correlated with those of expanded disability status score. In conclusion, serum IL-22 concentration may be a potential marker for MS disease severity and efficacy of treatment.
The sterile inflammatory response is an eminent contributor to acetaminophen (APAP)-hepatotoxicit... more The sterile inflammatory response is an eminent contributor to acetaminophen (APAP)-hepatotoxicity in humans. Recent advances unraveled an axial role of the NLRP3-inflammasome in APAP-post injury inflammation. Nevertheless, the role of signaling events preceded the NLRP3-inflammasome activation, like the transcription factor NF-κB and the purinergic receptor P2X7, is still unclear and needs further elucidation. Here, we investigated the pharmacological inhibition of these upstream signaling molecules by celastrol and brilliant blue G (BBG) (separately or simultaneously) in APAP-hepatotoxicity in mice. The results indicated that both celastrol and BBG pretreatments, especially when combined together, curbed APAP-induced hepatocellular injury (ALT, AST and LDH) and death (necrosis and apoptosis). The underlying mechanisms of protection of such combination against APAP-challenge were attributed to their efficient cooperation in: i) preventing the consumption of hepatic antioxidants (reduced glutathione and superoxide dismutase); ii) limiting the overproduction of lipid peroxidation aldehydes (malondialdehyde and 4-hydroxynonenal) and total nitrate/nitrite products; iii) attenuating the inflammatory cells accumulation in the liver, as evidenced by reducing the number of F4/80 positive cells/field in immunostaining and myeloperoxidase activity; iv) reversing the dysregulation in production of pro-inflammatory (TNF-α, IL-17A and IL-23) and anti-inflammatory (IL-10) cytokines; and v) enhancing the reparative capacity of injured hepatocytes, as demonstrated by increasing the percentage of PCNA positive hepatocytes per field of immunostaining. In conclusion, this murine study elicits a potential clinical applicability and therapeutic utility of celastrol and BBG combination in human cases of APAP-overdose hepatotoxicity.
Uploads
Papers by Mohamed E . Shaker