Safar, M. M., N. N. Shahin, A. F. Mohamed, and N. F. Abdelkader, "Suppression of BACE1 and amyloidogenic/RAGE axis by sitagliptin ameliorates PTZ kindling-induced cognitive deficits in rats.", Chemico-biological interactions, vol. 328, pp. 109144, 2020. Abstract

The debilitating nature of cognitive impairment in epilepsy and the potential of some traditional antiepileptics to further deteriorate cognitive function are areas of growing concern. Glucagon-like peptide-1 (GLP-1) deficiency has been linked to reduced seizure threshold as well as cognitive dysfunction. Here, we tested whether sitagliptin (SITA), by virtue of its neuroprotective properties, could alleviate both epilepsy and associated cognitive dysfunction in a rat model of kindling epilepsy. Chemical kindling was induced by subconvulsive doses of pentylenetetrazol (PTZ) (30 mg/kg; i.p). SITA (50 mg/kg; p.o) was administered 1 h before PTZ injections. SITA conceivably attenuated PTZ hippocampal histological insult, preserved neuronal integrity and amended neurotransmitter perturbations in rat hippocampi paralleled with enhanced hippocampal GLP-1 levels as well as the downstream cAMP content and protein kinase A (PKA) activity. Moreover, SITA improved cognitive functioning of rats in the Morris water maze which was coupled with hampered hippocampal p(Ser)-tau and β-amyloid proteins. SITA replenished p(Ser)-glycogen synthase kinase-3β (GSK-3β). It also opposed the boosted matrix metalloproteinase-9 (MMP-9), brain-derived neurotrophic factor (BDNF), and insulin-like growth factor-1 (IGF-1) levels associated with PTZ administration along with mitigation of both β-secretase-1 (BACE1) immunoreactivity and receptor for advanced glycation end products (RAGE) protein level in rat hippocampi. In conclusion, SITA subdues epileptic and cognitive upshots of PTZ kindling in rats, which might correspond to the modulation of BACE1, amyloidogenic/RAGE axis as well as GSK-3β/MMP-9/BDNF signaling cascade. SITA effects are probably mediated via boosting GLP-1 and subsequently enhancing GLP-1/GLP-1R signaling.

Abo-Elfadl, M. T., A. M. Gamal-Eldeen, M. F. Ismail, and N. N. Shahin, "Silencing of the cytokine receptor TNFRSF13B: A new therapeutic target for triple-negative breast cancer.", Cytokine, vol. 125, pp. 154790, 2020. Abstract

BACKGROUND: TNFRSF13B, TACI, is a member of the TNF receptor superfamily; it plays a key role in cancer cell proliferation and progression.

METHOD: Influence of silencing of human cytokine receptors on cell viability was screened by Luminescent Cell Viability Assay, after transfection of the siRNA library to find the maximum cell death superhits in both triple-negative MDA-MB-231 and double-positive MCF7 breast cells. The mode of cell death was investigated by dual DNA fluorescence staining. The expression of mRNAs of TACI, BAFF, BAFF-R, and APRIL was explored by qPCR. Immunocytofluorescence analysis was used to evaluate changes in TACI, Bcl-2, TNFR2, cyclin-D2, and PCNA. NF-kB p65, cell cycle, and necrosis/apoptosis (late and early) were analyzed by flow cytometry.

RESULTS: TACI is the most potent cytotoxic superhit resulted from high-throughput screening of the siRNA library, in both types of cells. Our findings indicated that silencing receptor TACI in both types of breast cancer cells led to significant cell death, after different intervals from siRNA transfection. Cell death mediators (TNFR2, Bcl-2, and NF-κB) were significantly decreased after TACI silencing. The key factors for cell division (Cyclin-D2 and PCNA) were significantly increased in silenced cells of both types but the cell cycle was arrested before the completion of mitosis. Expression of BAFF, BAFF-R and APRIL mRNA in TACI-silenced cells showed significant upregulation in MDA-MB-231 cells, while only BAFF-R and APRIL showed significant downregulation in MCF7 cells.

CONCLUSION: TACI silencing can be a new and promising therapeutic target for mesenchymal-stem like triple-negative breast cancer subtype.

Shahin, N. N., G. T. Abd-Elwahab, A. A. Tawfiq, and H. M. Abdelgawad, "Potential role of aryl hydrocarbon receptor signaling in childhood obesity.", Biochimica et biophysica acta. Molecular and cell biology of lipids, vol. 1865, issue 8, pp. 158714, 2020. Abstract

BACKGROUND: There is a growing concern that junk food has contributed to the childhood obesity epidemic. Recently, experimental studies suggested that the aryl hydrocarbon receptor (AHR) gene is strongly linked to western diet-induced obesity.

AIM: This study investigated the potential role of AHR signaling in childhood obesity and the possible associations of the AHR-aryl hydrocarbon receptor repressor (AHRR)-cytochrome P450 1B1 (CYP1B1) axis with fatty acid homeostasis and the appetite-related hormones, leptin and ghrelin.

SUBJECTS AND METHODS: The study included 80 children; 54 obese and 26 non-obese of matched age and sex. Demographic data, anthropometric measurements, and lipid profile were assessed. Expression of AHR signaling genes was analyzed in blood cells by qRT-PCR. Serum insulin, leptin and ghrelin levels were measured using ELISA.

RESULTS: The statistical power of this study, calculated using G*Power version, was 90% (α = 0.05). AHR and CYP1B1 gene expression levels were upregulated in the obese group compared to controls, whereas AHRR, stearoyl-CoA desaturase 1 (SCD1), and peroxisome proliferator-activated receptor-γ (PPARγ) were downregulated. Serum leptin correlated positively, while serum ghrelin correlated negatively with both AHR and CYP1B1. Stratification of obese children by age revealed more activated AHR signaling in younger than in older children. Receiver-operating-characteristic (ROC) analysis revealed that AHR, AHRR and CYP1B1 could discriminate between obese and normal weight children. Multivariate analysis showed that AHRR, CYP1B1 and ghrelin could be significant independent predictors of obesity.

CONCLUSION: This study provides new insights into the molecular mechanisms contributing to childhood obesity by revealing alterations in the AHR-AHRR-CYP1B1 axis, which could serve as a promising therapeutic target for childhood obesity.

Motawi, T. K., N. N. Shahin, A. S. Maghraby, M. Kirschfink, D. N. Abd-Elshafy, K. Awad, and M. M. Bahgat, "H1N1 Infection Reduces Glucose Level in Human U937 Monocytes Culture.", Viral immunology, vol. 33, issue 5, pp. 384-390, 2020. Abstract

Infection with influenza A (H1N1) virus contributes significantly to the global burden of acute respiratory diseases. Glucose uptake and metabolic changes are reported in different cell types after infections with different virus types, including influenza A virus. Alteration of glucose metabolism specifically in immune cells has major health consequences. The aim of this study was to monitor glucose concentration in unstimulated and stimulated U937 human monocytes with infectious or heat inactivated H1N1 or or in nonpathogenically stimulated monocytes with phorbol-12-myristate-13-acetate. Stimulated or unstimulated U937 human monocytes were subjected to H1N1 infection for different time points and the glucose profile in the growth medium was measured post infection. Results showed that regardless to whether the initial stimuli on U937 cells were of pathogen or nonpathogen origins, challenge infection by H1N1 causes a significant reduction of glucose levels 36 h post infection. In conclusion, H1N1 infection has a direct effect on the glucose uptake of U937 cells . This effect can be related to either H1N1 infection or cell differentiation status that might occur due to the exerted stimuli.

Motawi, T. M. K., N. A. H. Sadik, D. Sabry, N. N. Shahin, and S. A. Fahim, "rs2267531, a promoter SNP within glypican-3 gene in the X chromosome, is associated with hepatocellular carcinoma in Egyptians.", Scientific reports, vol. 9, issue 1, pp. 6868, 2019. Abstract

Hepatocellular carcinoma (HCC) is a major health concern in Egypt owing to the high prevalence of hepatitis C virus (HCV) infection. HCC incidence is characterized by obvious male predominance, yet the molecular mechanisms behind this gender bias are still unidentified. Functional variations in X-linked genes have more impact on males than females. Glypican-3 (GPC3) gene, located in the Xq26 region, has lately emerged as being potentially implicated in hepatocellular carcinogenesis. The current study was designed to examine the association of -784 G/C single nucleotide polymorphism (SNP) in GPC3 promoter region (rs2267531) with HCC susceptibility in male and female Egyptian HCV patients. Our results revealed a significant association between GPC3 and HCC risk in both males and females, evidenced by higher C allele and CC/C genotype frequencies in HCC patients when compared to controls. However, no such association was found when comparing HCV patients to controls. Moreover, GPC3 gene and protein expression levels were significantly higher in CC/C than in GG/G genotype carriers in males and females. The CC/C genotype exhibited a significant shorter overall survival than GG/G genotype in HCC patients. In conclusion, GPC3 rs2267531 on the X chromosome is significantly associated with HCC, but not with HCV infection, in the Egyptian population.

Shahin, N. N., N. A. El-Nabarawy, A. S. Gouda, and B. Mégarbane, "The protective role of spermine against male reproductive aberrations induced by exposure to electromagnetic field - An experimental investigation in the rat.", Toxicology and applied pharmacology, vol. 370, pp. 117-130, 2019. Abstract

The exponentially increasing use of electromagnetic field (EMF)-emitting devices imposes substantial health burden on modern societies with particular concerns of male infertility. Limited studies have addressed the modulation of this risk by protective agents. We investigated the hazardous effects of rat exposure to EMF (900 MHz, 2 h/day for 8 weeks) on male fertility and evaluated the possible protective effect of the polyamine, spermine, against EMF-induced alterations. Exposure to EMF significantly decreased sperm count, viability and motility, and increased sperm deformities. EMF-exposed rats exhibited significant reductions in serum inhibin B and testosterone along with elevated activin A, follicle-stimulating hormone, luteinizing hormone and estradiol concentrations. Testicular steroidogenic acute regulatory protein (StAR), c-kit mRNA expression and testicular activities of the key androgenic enzymes 3β- and 17β-hydroxysteroid dehydrogenases were significantly attenuated following exposure to EMF. Exposure led to testicular lipid peroxidation, decreased catalase and glutathione peroxidase activities and triggered nuclear factor-kappa B p65, inducible nitric oxide synthase, cyclooxygenase-2 and caspase-3 overexpression. EMF-exposed rats showed testicular DNA damage as indicated by elevated comet parameters. Spermine administration (2.5 mg/Kg/day intraperitoneally for 8 weeks) prevented EMF-induced alterations in the sperm and hormone profiles, StAR and c-kit expression and androgenic enzyme activities. Spermine hampered EMF-induced oxidative, inflammatory, apoptotic and DNA perturbations. Histological and histomorphometric analysis of the testes supported all biochemical findings. In conclusion, rat exposure to EMF disrupts sperm and hormone profiles with underlying impairment of steroidogenesis and spermatogenesis. Spermine confers protection against EMF-associated testicular and reproductive aberrations, at least in part, via antioxidant, anti-inflammatory and anti-apoptotic mechanisms.

Ali, S. O., N. N. Shahin, M. M. Safar, and S. M. Rizk, "Therapeutic potential of endothelial progenitor cells in a rat model of epilepsy: Role of autophagy", Journal of Advanced Research, vol. 18, pp. 101 - 112, 2019. AbstractWebsite

Epilepsy is one of the most well-known neurological conditions worldwide. One-third of adult epileptic patients do not respond to antiepileptic drugs or surgical treatment and therefore suffer from the resistant type of epilepsy. Stem cells have been given substantial consideration in the field of epilepsy therapeutics. The implication of pathologic vascular response in sustained seizures and the eminent role of endothelial progenitor cells (EPCs) in maintaining vascular integrity tempted us to investigate the potential therapeutic effects of EPCs in a pentylenetetrazole (PTZ)-induced rat model of epilepsy. Modulation of autophagy, a process that enables neurons to maintain an equilibrium of synthesis, degradation and subsequent reprocessing of cellular components, has been targeted. Intravenously administered EPCs homed into the hippocampus and amended the deficits in memory and locomotor activity. The cells mitigated neurological damage and the associated histopathological alterations and boosted the expression of brain-derived neurotrophic factor. EPCs corrected the perturbations in neurotransmitter activity and enhanced the expression of the downregulated autophagy proteins light chain protein-3 (LC-3), beclin-1, and autophagy-related gene-7 (ATG-7). Generally, these effects were comparable to those achieved by the reference antiepileptic drug, valproic acid. In conclusion, EPCs may confer therapeutic effects against epilepsy and its associated behavioural and biochemical abnormalities at least in part via the upregulation of autophagy. The study warrants further research in experimental and clinical settings to verify the prospect of using EPCs as a valid therapeutic strategy in patients with epilepsy.

Abdelmonem, M., N. N. Shahin, L. A. Rashed, H. A. A. Amin, A. A. Shamaa, and A. A. Shaheen, "Hydrogen sulfide enhances the effectiveness of mesenchymal stem cell therapy in rats with heart failure: In vitro preconditioning versus in vivo co-delivery.", Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie, vol. 112, pp. 108584, 2019 Feb 18. Abstract

Stem cell therapy represents a promising therapeutic avenue for cardiac disorders, including heart failure. Although stem cell transplantation showed encouraging preliminary results, the outcomes of clinical studies are still unsatisfactory. This study aimed to compare the outcomes of two therapeutic approaches, in vivo co-delivery of sodium hydrogen sulfide (NaHS) concomitant with bone marrow-derived mesenchymal stem cell (BMSC) transplantation and in vitro preconditioning of BMSCs with NaHS, both of which are intended to promote the success of stem cell therapy in rats with isoprenaline-induced heart failure. Heart failure developed 4 weeks after the subcutaneous injection of isoprenaline (170 mg/kg) for 4 consecutive days. The in vivo approach involved the co-delivery of intraperitoneally administered NaHS concomitant with BMSC transplantation for a period of 14 days. The in vitro approach involved preconditioning BMSCs with NaHS for 30 min before transplantation. Compared to treatment with BMSCs alone, in vitro preconditioning of BMSCs with NaHS improved left ventricular function as measured by echocardiography and electrocardiography and enhanced stem cell homing, proliferation and differentiation as manifested by higher cardiac expression of GATA-4 and myocyte enhancer factor 2. Moreover, the measurement of cardiac transforming growth factor beta 1 levels and histopathological investigation revealed mitigated fibrosis and myocardial injury scores. Compared with BMSC therapy alone, the in vivo approach enhanced stem cell homing and differentiation, alleviated fibrosis and augmented vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) expression. In conclusion, NaHS can potentiate the efficiency of BMSC therapy for heart failure by in vitro preconditioning or in vivo co-delivery. The in vitro approach is superior with regard to improving cardiac function in addition to enhancing stem cell proliferation, while the in vivo approach is superior with regard to increasing cardiac VEGF and eNOS expression.

Motawi, T. K., M. R. Mohamed, N. N. Shahin, M. A. M. Ali, and M. A. Azzam, "Time-course expression profile and diagnostic potential of a miRNA panel in exosomes and total serum in acute liver injury.", The international journal of biochemistry & cell biology, vol. 100, pp. 11-21, 2018 Jul. Abstract

Circulating miRNAs have recently emerged as attractive candidates for biomarker discovery. However, they have a variant distribution in circulation, and the diagnostic significance of their compartmentalization is yet to be elucidated. This study explored the time-course expression profile and the diagnostic potential of miRNAs-122a-5p, 192-5p, 193a-3p and 194-5p in exosomal and total serum compartments in two rat models of acute liver injury (ALI). Exosomes were isolated and characterized in terms of morphology, size and CD-63 surface marker expression. Exosomal, serum and hepatic miRNAs were quantified using q-RT-PCR. An inverse expression pattern of hepatic and total serum miRNAs was observed following acetaminophen or thioacetamide-induced liver injury. Conversely, exosomal miRNAs expression pattern varied according to the type of injury. Overall, ROC analysis revealed superior discriminatory ability of exosomal miRNA-122a-5p following either acetaminophen or thioacetamide injury with earlier diagnostic potential and a wider diagnostic window compared to the corresponding total serum counterpart. Moreover, exosomal miRNAs showed higher correlation with ALT activity in both models. In conclusion, exosomal miRNA-122a-5p shows higher diagnostic performance with a broader diagnostic time window and an earlier diagnostic potential than its serum counterpart in ALI. Furthermore, exosomal miRNAs-122a-5p, 192-5p and 193a-3p exhibit an injury-specific signature in ALI and can be used not only as diagnostic tools in liver injury but also to differentiate between different etiologies of injury.

Shahin, N. N., N. F. Abdelkader, and M. M. Safar, "A Novel Role of Irbesartan in Gastroprotection against Indomethacin-Induced Gastric Injury in Rats: Targeting DDAH/ADMA and EGFR/ERK Signaling.", Scientific reports, vol. 8, issue 1, pp. 4280, 2018 Mar 09. Abstract

The advent of angiotensin II type 1 receptor blockers (ARBs) as intriguing gastroprotective candidates and the superior pharmacokinetics and pharmacodynamics displayed by irbesartan compared to many other ARBs raised the interest to investigate its gastroprotective potential in a rat model of gastric injury. Irbesartan (50 mg/Kg) was orally administered to male Wistar rats once daily for 14 days; thereafter gastric injury was induced by indomethacin (60 mg/Kg, p.o). Irbesartan reduced gastric ulcer index, gastric acidity, and ameliorated indomethacin-induced gastric mucosal apoptotic and inflammatory aberrations, as demonstrated by hampering caspase-3, prostaglandin E and tumor necrosis factor-alpha levels and cyclooxygenase-2 mRNA expression. This ARB increased mucosal dimethylarginine dimethylaminohydrolase-1 (DDAH-1) gene expression and decreased elevated levels of matrix metalloproteinase-9, asymmetric dimethylarginine (ADMA), epidermal growth factor receptor (EGFR) mRNA and phosphorylated extracellular signal-regulated kinase 1 and 2 (pERK1/2). Histopathological evaluation corroborated biochemical findings. Overall efficacy of irbesartan was comparable to ranitidine, the widely used H receptor blocker. In conclusion, irbesartan exerts significant gastroprotection against indomethacin-induced mucosal damage via acid-inhibitory, anti-inflammatory, anti-apoptotic and extracellular matrix remodeling mechanisms that are probably mediated, at least partly, by down-regulating DDAH/ADMA and EGFR/ERK1/2 signaling.