Mohamed El-Mesery

MLN4924 sensitizes monocytes and maturing dendritic cells for TNF-dependent and -independent necroptosis

MLN4924 prevents the formation of active cullin‐RING ubiquitin ligase complexes and thus inhibits NF‐κB signalling. Here, we evaluated the effects of this compound on monocytes and dendritic cells (DCs).

Glycyrrhizin ameliorates high fat diet-induced obesity in rats by activating NrF2 pathway

Aim: Obesity based on insulin resistance is a state of chronic oxidative stress and inflammation that are highly regulated through nuclear factor Erythroid 2‐related factor 2 (NrF2) pathway. Materials and methods: 70 male Wistar rats were randomized into two models. The prophylactic model was 10 weeks and rats were grouped into: normal group, GL group (received glycyrrhizin 50 mg/kg/day orally along with normal pellet diet), HFD group and HFD+ GL group (received glycyrrhizin along with HFD). The treatment model was 14 weeks and rats were grouped into: normal group, HFD group and HFD + GL group (received glycyrrhizin from the week 10). Key findings: Glycyrrhizin decreased significantly rat weights and insulin resistance, normalized lipid profile and reduced significantly the adipocytes size in adipose tissue and lipid deposition in the liver tissue through histopathologic examination. Furthermore, glycyrrhizin ameliorated obesity‐induced oxidative stress which indicated by significant decrease in liver malondialdehyde level (P < 0.001) and increase in the total antioxidant capacity (P < 0.001). Interestingly, molecular mechanism of glycyrrhizin was explored, that included significant reduction of liver gluconeogenic enzymes mRNA expression (P < 0.001), a significant increase of liver insulin receptor, NrF2 and homooxygenase‐1 mRNA expressions (P < 0.001) and significant increase and nuclear translocation of NrF2 in liver tissue. Significance: Glycyrrhizin ameliorates HFD‐induced obesity in rats that may be attributed to its ability to increase insulin receptor expression and to activate NrF2 and subsequent homooxygenase‐1 pathway. Thus, this work represents a safe natural compound (glycyrrhizin) that has a great role either as prophylaxis or treatment for insulin resistance related to obesity. Graphical abstract: The effect of high fat diet (HFD) feeding either for 10 or 14 weeks on rats (A), the proposed mechanism of glycyrrhizin either as prophylaxis or treatment in amelioration of obesity‐associated with insulin resistance induced by high fat diet (HFD) feeding in rats (B). G6Pase: glucose‐6‐phosphatase, HDL‐C: high density lipoprotein‐cholesterol, HO‐1: homooxygenase‐1, HOMA IR: homeostatic model assessment of insulin resistance, LDL‐C: low density lipoprotein‐cholesterol, MDA: malondialdehyde, NrF2: nuclear factor erythroid‐derived factor 2‐related factor 2, PEPCK: phosphoenolpyruvate carboxykinase, TAC: total antioxidant capacity. Figure. No Caption available.

Silymarin and caffeine combination ameliorates experimentally-induced hepatic fibrosis through down-regulation of LPAR1 expression

AIMS Lysophosphatidic acid is a lipid mediator that is supposed to be implicated in hepatic fibrosis. Silymarin and caffeine are natural compounds known for their anti-inflammatory and antioxidant effects. Our study aimed to explore the effect of silymarin, caffeine, and their combination on lysophosphatidic acid receptor 1 (LPAR1) pathway in thioacetamide (TAA)-induced hepatic fibrosis. MAIN METHODS Hepatic fibrosis was induced in male Sprague-Dawley rats by intraperitoneal injection of 200 mg/kg of TAA twice a week for 8 weeks. Silymarin (50 mg/kg), caffeine (50 mg/kg), and their combination (50 mg/kg silymarin + 50 mg/kg caffeine) were orally given to rats every day for 8 weeks along with TAA injection. Liver functions were measured. Histopathological examination of liver tissues was performed using hematoxylin and eosin and Massons trichrome staining. mRNA expressions of LPAR1, transforming growth factor beta 1 (TGF-β1), connective tissue growth factor (CTGF), and alpha smooth muscle actin (α-SMA) were measured using RT-PCR. LPAR1 tissue expression was scored using immunohistochemistry. KEY FINDINGS Silymarin, caffeine, and their combination significantly improved liver function. They caused significant decrease in fibrosis and necro-inflammatory scores. Combination of silymain and caffeine caused a significant decrease in the necro-inflammatory score than the single treatment with silymarin or caffeine. In addition, silymarin, caffeine, and their combination significantly decreased hepatic LPAR1, TGF-β1, CTGF, and α-SMA gene expressions and LPAR1 tissue expression. SIGNIFICANCE Silymarin, caffeine, and their combination protect against liver fibrosis through down-regulation of LPAR1, TGF-β1, and CTGF.

The novel c-Met inhibitor capmatinib mitigates diethylnitrosamine acute liver injury in mice

The receptor tyrosine kinase mesenchymal-epithelial transition factor (c-Met) sits at the interface between controlled cellular division of organogenesis and uncontrolled cellular division of carcinogenesis. c-Met contribution to the initial phases of liver injury and inflammation is still not resolved. Herein, we investigated the selective pharmacological intervention of c-Met by capmatinib (formerly known as INC280) in the diethylnitrosamine (DEN) acute liver injury model in mice. c-Met inhibition by capmatinib reduced DEN-induced elevation of the pro-inflammatory cytokines TNF-α, IL-1β, IL-17A, IL-23(p19/40) and IFN-γ, which correlated well with serum markers of hepatocellular injury (ALT, AST and LDH). The protective effects possessed by capmatinib were mainly mediated by inhibiting inflammatory cells infiltration to the liver. However, hematoxylin-eosin and bax-immunohistochemical stainings revealed that capmatinib (at a dose of 10, but not 5mg/kg) aggravated DEN-induced hepatocellular ballooning and apoptosis, respectively. These effects were concordant with hepatocellular overexpression of the amino acid transporter CD98. Such capmatinib effects arised mostly from exaggerating the elevation of the mutagenic lipid peroxide 4-HNE along with MDA that enhanced DEN-induced compensatory proliferation evidenced by PCNA expression. In conclusion, inhibition of c-Met activation by capmatinib may provide protection against liver injury, but may trigger undesirable elevation of the mutagenic 4-HNE.

Vitamin D potentiates anti-tumor activity of 5-fluorouracil via modulating caspase-3 and TGF-β1 expression in hepatocellular carcinoma-induced in rats

We investigated the role of vitamin D (Vit D) alone and in combination with 5-fluorouracil (5-FU) in thioacetamide (TAA)-induced hepatocellular carcinoma (HCC) in rats. Fifty male Sprague-Dawley rats were randomized into a control group and 4 groups that received TAA (200 mg/kg, i.p.) twice per week for 16 weeks. These 4 groups were further divided as follows: HCC group; 5-FU group (75 mg/kg, i.p., once weekly for 3 weeks starting from the 12th week); Vit D group (200 IU/kg daily by oral tube for 16 weeks); and 5-FU + Vit D group (received the previously mentioned dosage regimens of 5-FU and Vit D). HCC was detected by histopathological changes in liver sections and the elevation of serum α-fetoprotein (AFP). Treatment with 5-FU + Vit D significantly decreased gene expression of nuclear factor erythroid 2-related factor 2 (NrF2) and transforming growth factor β1 (TGF-β1) at both the gene and protein level and serum AFP concentrations in comparison with their corresponding monotherapy. Moreover, 5-FU + Vit D treatment enhanced apoptosis by increasing caspase-3 gene and protein expression. Conclusively, Vit D enhances antitumor activity of 5-FU in an HCC-induced model and improves liver function of treated animals. Combination therapy in a TAA-induced HCC rat model was more effective than 5-FU or Vit D through the modulation of TGF-β1, caspase-3, and NrF2 expressions.

Effects of Metformin on Apoptosis and Alpha Synuclein in Rat Model of Pentylenetetrazole-induced Epilepsy

The present study was designed to examine the possible neuroprotective and antiepileptic effects of metformin (Metf) in a rat model of pentylenetetrazole (PTZ)-induced epilepsy and its possible underlying mechanisms. Forty male albino rats were assigned to 4 groups of equal size: (1) normal control (NC) group, (2) Metf group: daily treatment with Metf (200 mg/kg, i.p.) for 2 weeks, (3) PTZ group: treatment with PTZ (50 mg/kg, i.p.) every other day for 2 weeks, and (4) Metf + PTZ group: daily treatment with PTZ and metformin (200 mg/kg, i.p.) for 2 weeks. Administration of PTZ caused a significant increase in seizure score and duration, induced a state of oxidative stress (high malondialdehyde, low reduced glutathione and catalase activity), and led to the upregulation of β-catenin, caspase-3, and its cleavage products, Hsp70 and α-synuclein, in hippocampal regions as well as a significant reduction in seizure latency. While Metf treatment significantly ameliorated PTZ-induced seizures, attenuated oxidative stress, and upregulated α-synuclein and β-catenin expression, it also inhibited caspase-3 activation and the release of the cleavage product and caused more upregulation in Hsp70 expression in hippocampal regions (p < 0.05). In conclusion, the antiepileptic and neuroprotective effects of Metf in PTZ-induced epilepsy might be due to the inhibition of apoptosis, attenuation of oxidative stress and α-synuclein expression, and upregulation of Hsp70.

l-Carnitine Modulates Epileptic Seizures in Pentylenetetrazole-Kindled Rats via Suppression of Apoptosis and Autophagy and Upregulation of Hsp70

l-Carnitine is a unique nutritional supplement for athletes that has been recently studied as a potential treatment for certain neuropsychiatric disorders. However, its efficacy in seizure control has not been investigated. Sprague Dawley rats were randomly assigned to receive either saline (Sal) (negative control) or pentylenetetrazole (PTZ) 40 mg/kg i.p. × 3 times/week × 3 weeks. The PTZ group was further subdivided into two groups, the first received oral l-carnitine (l-Car) (100 mg/kg/day × 4 weeks) (PTZ + l-Car), while the second group received saline (PTZ + Sal). Daily identification and quantification of seizure scores, time to the first seizure and the duration of seizures were performed in each animal. Molecular oxidative markers were examined in the animal brains. l-Car treatment was associated with marked reduction in seizure score (p = 0.0002) that was indicated as early as Day 2 of treatment and continued throughout treatment duration. Furthermore, l-Car significantly prolonged the time to the first seizure (p < 0.0001) and shortened seizure duration (p = 0.028). In addition, l-Car administration for four weeks attenuated PTZ-induced increase in the level of oxidative stress marker malondialdehyde (MDA) (p < 0.0001) and reduced the activity of catalase enzyme (p = 0.0006) and increased antioxidant GSH activity (p < 0.0001). Moreover, l-Car significantly reduced PTZ-induced elevation in protein expression of caspase-3 (p < 0.0001) and β-catenin (p < 0.0001). Overall, our results suggest a potential therapeutic role of l-Car in seizure control and call for testing these preclinical results in a proof of concept pilot clinical study.

Molecular Design and Synthesis of New 3,4-Dihydropyrimidin-2(1H)-Ones as Potential Anticancer Agents with VEGFR-2 Inhibiting Activity

BACKGROUND Two series of 3,4-dihydropyrimidin-2(1H)-one derivatives were designed based on the main structural features characterizing reported anticancer compounds with potent VEGFR-2 inhibiting activity. Target compounds were synthesized, and investigated for their in vitro anticancer activity. RESULT Of these derivatives, compound 8b possessed significant activity against Caco-2 (IC50 of 24.9 µM) and MCF7 (IC50 of 29.4 µM), compound 10 showed excellent potency against HCT-116 (IC50 of 32.6 µM), HEPG2 (IC50 of 16.4 µM) and MCF7 (IC50 of 32.8 µM), while compound 11b exhibited moderate anticancer activity towards MCF7 (IC50 of 41.7µM). Both 8b and 10 exhibited good potency regarding inhibition of vascular endothelial growth factor receptor 2 (VEGFR-2), with IC50 of 14.00 and 21.62 nM, respectively. CONCLUSION The activity was rationalized based on molecular docking study that supported their VEGFR-2 inhibitory activity; as indicated by their favorable binding with the active site.

Molecular analysis of Hepatitis B virus sub-genotypes and incidence of preS1/preS2 region mutations in HBV-infected Egyptian patients from Mansoura†

Hepatitis B virus (HBV) is one of the major causes of viral hepatitis worldwide. Despite the prevalence of HBV infection in Egypt, few studies have focused on sub‐genotyping of the virus. Moreover, no studies are available regarding the mutational analysis of the preS1/preS2 region of the viral genome, or its impact on hepatocellular carcinoma (HCC) development in Egypt. In this study, we have analyzed the sub‐genotypes and incidence of mutations in the preS1/preS2 region of HBV present in HBV‐infected patients, from Mansoura city (located in the center of Nile Delta region of Egypt), via partial sequencing of this specific region. Moreover, we have investigated the impact of these mutations on HCC development by measuring serum alpha fetoprotein (AFP) level and abdominal ultrasound examination of the HBV‐infected patients. According to our results, all samples were genotype D in which sub‐genotype D1 was predominant. In addition, the results revealed mutations in the preS1/preS2 region, which could result in either immature preS1 protein or completely inhibit the translation of the preS2 protein. However, there was no incidence of HCC development in patients infected with mutated HBV in the preS1/preS2 region. In summary, for the first time our work has proved the predominance of sub‐genotype D1 among HBV‐infected Egyptian patients in Mansoura city, Nile Delta region, Egypt, and incidence of mutations in the preS1/preS2 region of HBV genome. This current study opens up research opportunities to discuss the impact of HBV mutations on the development of HCC in Egypt.

The SMAC mimetic BV6 induces cell death and sensitizes different cell lines to TNF-α and TRAIL-induced apoptosis.

The inhibitors of apoptosis proteins are implicated in promoting cancer cells survival and resistance toward immune surveillance and chemotherapy. Second mitochondria-derived activator of caspases (SMAC) mimetics are novel compounds developed to mimic the inhibitory effect of the endogenous SMAC/DIABLO on these IAPs. Here, we examined the potential effects of the novel SMAC mimetic BV6 on different human cancer cell lines. Our results indicated that BV6 was able to induce cell death in different human cancer cell lines. Mechanistically, BV6 dose dependently induced degradation of IAPs, including cIAP1 and cIAP2. This was coincided with activating the non-canonical NF-kappa B (NF-κB) pathway, as indicated by stabilizing NF-κB-inducing kinase (NIK) for p100 processing to p52. More interestingly, BV6 was able to sensitize some of the resistant cancer cell lines to apoptosis induced by the death ligands tumor necrosis factor-α (TNF-α) and TNF-related apoptosis-inducing ligand (TRAIL) that are produced by different cells of the immune system. Such cell death enhancement was mediated by inducing an additional cleavage of caspase-9 to augment that of caspase-8 induced by death ligands. This eventually led to more processing of the executioner caspase-3 and poly (ADP-ribose) polymerase (PARP). In conclusion, therapeutic targeting of IAPs by BV6 might be an effective approach to enhance cancer regression induced by immune system. Our data also open up the future possibility of using BV6 in combination with other antitumor therapies to overcome cancer drug resistance.