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Abdallah E Abdallah,1 Reda R Mabrouk,1 Mohamed R Elnagar,2 Amel Mostafa Farrag,3 Mohamed H Kalaba,4 Mohamed H Sharaf,4 Esmail M El-Fakharany,5 Dina Abed Bakhotmah,6 Eslam B Elkaeed,7 Maged Mohammed Saleh Al Ward1 1Pharmaceutical Medicinal Chemistry & Drug Design Department, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, 11884, Egypt; 2Department of Pharmacology and Toxicology, Faculty of Pharmacy, Al-Azhar University, Cairo, 11884, Egypt; 3Pharmaceutical Chemistry Department, Faculty of Pharmacy (Girls), Al-Azhar University, Cairo, Egypt; 4Botany and Microbiology Department, Faculty of Science, Al-Azhar University, Cairo, 11884, Egypt; 5Protein Research Department, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, New Borg El Arab, Egypt; 6Chemistry Department, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia; 7Department of Pharmaceutical Sciences, College of Pharmacy, AlMaarefa University, Riyadh, 13713, Saudi ArabiaCorrespondence: Abdallah E Abdallah; Maged Mohammed Saleh Al Ward, Pharmaceutical Medicinal Chemistry & Drug Design Department, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, 11884, Egypt, Email Abdulla_emara@azhar.edu.eg; majed1000ward@hotmail.comBackground: Cancer is still a major world health threat, causing a high rate of mortality. VEGFR-2 inhibitor anticancer agents are of great significance. However, they showed some serious side effects.Purpose: To discover new effective and safer anticancer agents, a new series of piperazinylquinoxaline-based derivatives was designed and synthesized on the basis of the pharmacophoric features of VEGFR-2 inhibitor drugs.Methods: The new candidates were evaluated against A549 lung cancer cells, HepG-2 hepatoma cells, Caco-2 colon cancer cells, MDA breast cancer cells, and VEGFR-2 kinase. Moreover, cell cycle kinetics and apoptosis rates were studied in HepG-2 cells treated with compound 11, which was the most promising candidate.Results: The new derivatives revealed better antitumor results (IC50 from 6.48 to 38.58 μM) against the aforementioned cancer cell lines than sorafenib. Also, the new candidates showed VEGFR-2 inhibition with IC50 values ranging from 0.19 to 0.60 μM compared to 0.08 μM for sorafenib. Compound 11, meanwhile, showed IC50 values equal to 10.61, 9.52, 12.45, 11.52, and 0.19 μM against the cancer cell lines and VEGFR-2, respectively. Moreover, compound 11 raised the apoptosis rate in HepG-2 cells from 5% to 44% and caused 4, 2.3, and 3-fold increases in BAX/Bcl-2 ratio, caspase-3 level, and P53 expression, respectively, compared to control untreated cells. Finally, the new derivatives displayed the correct binding mode into VEGFR-2 kinase pocket, giving interactions with the essential residues.Conclusion: This work suggests that compound 11 is a very significant anticancer candidate, and piperazinylquinoxaline is an important scaffold in the development of new potential effective and safer VEGFR-2 inhibitor agents.Keywords: anticancer, apoptosis, molecular modeling, piperazinylquinoxaline, VEGFR-2 kinase, Western blot

Design and virtual screening of a set of non-acidic 4-methyl-4-phenyl-benzenesulfonate-based aldose reductase 2 inhibitors had been developed followed by chemical synthesis. Based on the results, the synthesized compounds 2, 4a,b, 7a-c, 9a-c, 10a-c, 11b,c and 14a-c inhibited the ALR2 enzymatic activity in a submicromolar range (99.29-417 nM) and among them, the derivatives 2, 9b, 10a and 14b were able to inhibit ALR2 by IC 50 of 160.40, 165.20, 99.29 and 120.6 nM, respectively. Moreover, kinetic analyses using Lineweaver-Burk plot revealed that the most active candidate 10a inhibited ALR2 potently via a non-competitive mechanism. In vivo studies showed that 10 mg/kg of compound 10a significantly lowered blood glucose levels in alloxan-induced diabetic mice by 46.10 %. Moreover, compound 10a showed no toxicity up to a concentration of 50 mg/kg and had no adverse effects on liver and kidney functions. It significantly increased levels of GSH and SOD while decreasing MDA levels, thereby mitigating oxidative stress associated with diabetes and potentially attenuating diabetic complications. Furthermore, the binding mode of compound 10a was confirmed through MD simulation. Noteworthy, compounds 2 and 14b showed moderate antimicrobial activity against the two fungi Aspergillus fumigatus and Aspergillus niger. Finally, we report the thiazole derivative 10a as a new promising non-acidic aldose reductase inhibitor that may be beneficial in treating diabetic complications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Cancer is a critical health problem, and chemotherapy administration is mandatory for its eradication. However, chemotherapy like doxorubicin (Dox) has serious side-effects including cognitive impairment or chemo brain. Melatonin is a neuroprotective agent that has antioxidant, and anti-inflammatory effects. We aimed to explore melatonin's effect on Dox-induced chemo brain to discover new mechanisms associated with Dox-induced neurotoxicity and try to prevent its occurrence. Thirty-two male albino rats had been equally divided into four groups; control, melatonin-administrated, Dox-induced chemo brain, and melatonin + Dox treated. On the 9th day, brain had been excised after scarification and had been assessed for reactive oxygen species measurement, histopathological analysis, immunohistochemical, gene and protein expressions for the nuclear factor erythroid 2-related factor 2 (Nrf2), p53 and Silent information regulator 2 homolog 1 (SIRT1). Our results show that melatonin coadministration diminished Dox induced hippocampal and prefrontal cortex (PFC) cellular degeneration. It alleviated Nitric Oxide (NO) level and reversed the decline of antioxidant enzyme activities. It also upregulated Nrf2, SIRT1 and downregulated p53 gene expression in rats receiving Dox. Moreover, melatonin elevated the protein expression level of Nrf2, SIRT1 and reduced p53 corresponding to immunohistochemical results. The data suggested that melatonin can mitigate Dox-induced neurotoxicity by aggravating the endogenous antioxidants and inducing neurogenesis through activation of Nrf2/p53-SIRT1signaling pathway in adult rats' PFC. These effects were associated with Nrf2, SIRT1 activation and p53 inhibition. This could be guidance to add melatonin as an adjuvant supplement to Dox regimens to limit its adverse effect on the brain function., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

This research study describes the development of new small molecules based on 2,4-thiazolidinedione (2,4-TZD) and their aldose reductase (AR) inhibitory activities. The synthesis of 17 new derivatives of 2,4-TZDs hybrids was feasible by incorporating two known bioactive scaffolds, benzothiazole heterocycle, and nitro phenacyl moiety. The most active hybrid ( 8b ) was found to inhibit AR in a non-competitive manner (0.16 µM), as confirmed by kinetic studies and molecular docking simulations. Furthermore, the in vivo experiments demonstrated that compound 8b had a significant hypoglycaemic effect in mice with hyperglycaemia induced by streptozotocin. Fifty milligrams per kilogram dose of 8b produced a marked decrease in blood glucose concentration, and a lower dose of 5 mg/kg demonstrated a noticeable antihyperglycaemic effect. These outcomes suggested that compound 8b may be used as a promising therapeutic agent for the treatment of diabetic complications.

Berberine (Berb) is a major alkaloid with potential protective effects against multiple neurological disorders. Nevertheless, its positive effect against 3-nitropropionic acid (3NP) induced Huntington's disease (HD) modulation has not been fully elucidated. Accordingly, this study aimed to assess the possible action mechanisms of Berb against such neurotoxicity using an in vivo rats model pretreated with Berb (100 mg/kg, p.o.) alongisde 3NP (10 mg/kg, i.p.) at the latter 2 weeks to induce HD symptoms. Berb revealed its capacity to partially protect the striatum as mediated via the activation of BDNF-TrkB-PI3K/Akt signaling and amelioration of neuroinflammation status by blocking NF-κB p65 with a concomitant reduction in its downstream cytokines TNF-α and IL-1β. Moreover, its antioxidant potential was evidenced from induction of Nrf2 and GSH levels concurrent with a reduction in MDA level. Furthermore, Berb anti-apoptotic effect was manifested through the induction of pro-survival protein (Bcl-2) and down-regulation of the apoptosis biomarker (caspase-3). Finally, Berb intake ascertained its striatum protective action by improving the motor and histopathological abnormalities with concomitant dopamine restoration. In conclusion, Berb appears to modulate 3NP-induced neurotoxicity by moderating BDNF-TrkB-PI3K/Akt signaling besides its anti-inflammatory, antioxidant, as well as anti-apoptotic effect., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by gradual cognitive decline. Strong antioxidants that inhibit free radicals, such as polyphenols, reduce the likelihood of developing oxidative stress-related degenerative diseases such as AD. Naringin, a flavonoid found in citrus fruit shown to be neuroprotective, reduce oxidative damage and minimize histopathological changes caused by ischemic reperfusion, enhance the long-term memory in AD animal models. This work aimed to comprehend the role of naringin in the defense of the cerebellum against aluminum chloride (AlCl 3 )-induced AD in rats by investigating the behavioral, neurochemical, immunohistochemical, and molecular mechanisms that underpin its possible neuroprotective effects. Twenty-four adult albino rats were divided into four groups ( n = 6/group): (i) Control (C) received saline per oral (p.o.), (ii) Naringin( N )-received naringin (100 mg/kg/d) p.o, (iii) AlCl 3 -recived AlCl 3 (100 mg/kg/d) p.o and (iv) AlCl 3 + Naringin (AlCl 3 + N ) received both AlCl 3 and naringin p.o for 21 days. Behavioral tests showed an increase in the time to reach the platform in Morris water maze, indicating memory impairment in the AlCl 3 -treated group, but co-administration of naringin showed significant improvement. The Rotarod test demonstrated a decrease in muscle coordination in the AlCl 3 -treated group, while it was improved in the AlCl 3 + N group. Neurochemical analysis of the hippocampus and cerebellum revealed that AlCl 3 significantly increased lipid peroxidation and oxidative stress and decreased levels of reduced glutathione. Administration of naringin ameliorated these neurochemical changes via its antioxidant properties. Cerebellar immunohistochemical expression for microtubule assembly (tau protein) and oxidative stress (iNOS) increased in A1C1 3 -treated group. On the other hand, the expression of the autophagic marker (LC3) in the cerebellum showed a marked decline in AlCl 3 -treated group. Western blot analysis confirmed the cerebellar immunohistochemical findings. Collectively, these findings suggested that naringin could contribute to the combat of oxidative and autophagic stress in the cerebellum of AlCl 3 -induced AD., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer AE-k declared a shared affiliation with the authors EMEN, MA, and ZA-Q to the handling editor at the time of review., (Copyright © 2022 Hassan, Elnagar, Abdelrazik, Mahdi, Hamza, Elattar, ElNashar, Alghamdi, Al-Qahtani, Al-Khater, Aldahhan and ELdesoqui.)

There is a huge demand for novel anticancer agents with fewer side effects compared to current therapies. Pitaya, or dragon fruit, is a reservoir of potent anticancer compounds. This research aimed to analyze the phytochemical components of Hylocereus undatus pulp and peel extracts using LC-MS and GC-MS, and to investigate the in vitro effects of both extracts against cancer (breast, MCF-7, and colon, Caco-2) and normal (lung; WI-38 and breast; MCF-10A) cell proliferation using the MTT assay. The apoptosis potential of the anticancer effects was also evaluated using flow cytometry, RT-PCR, and Western blot. The total phenolic and flavonoid contents in the peel extract were significantly higher than those in the pulp extract. Compared to the flavonoid and phenolic acid standards, the LC-MS analysis revealed the presence of nine compounds, which were represented as 84.32 and 5.29 µg/g of the flavonoids and 686.11 and 148.72 µg/g of the phenolic acids in the peel and pulp extracts, respectively. Among the identified compounds, chlorogenic acid, caffeic acid, ferulic acid, and rutin were found at the highest concentration in both plant extracts. Both extracts displayed cytotoxic activity against MCF-7 and Caco-2 cancer cells after 48 h of treatment at IC 50 values ranging from 14 to 53 μg/mL with high selective indices against normal WI-38 and MCF-10A cell lines. The increase in apoptosis was revealed by the overexpression of p53, BAX, and caspase-9 and the downregulation of antiapoptotic Bcl-2 mRNA and protein expressions. The results indicate that H. undatus extracts can be a plant source for cancer therapy.

Colorectal cancer therapies have produced promising clinical responses, but tumor cells rapidly develop resistance to these drugs. It has been previously shown that EC19 and EC23, two EC-synthetic retinoids, have single-agent preclinical anticancer activity in colorectal carcinoma. Here, isobologram analysis revealed that they have synergistic cytotoxicity with retinoic acid receptor (RAR) isoform-selective agonistic retinoids such as AC261066 (RARβ2-selective agonist) and CD437 (RARγ-selective agonist) in Caco-2 cells. This synergism was confirmed by calculating the combination index (lower than 1) and the dose reduction index (higher than 1). Flow cytometry of combinatorial IC 50 (the concentration causing 50% cell death) confirmed the cell cycle arrest at the SubG 0 -G 1 phase with potentiated apoptotic and necrotic effects. The reported synergistic anticancer activity can be attributed to their ability to reduce the expression of ATP-binding cassette (ABC) transporters including P-glycoprotein (P-gp1), breast cancer resistance protein (BCRP) and multi-drug resistance-associated protein-1 (MRP1) and Heat Shock Protein 70 (Hsp70). This adds up to the apoptosis-promoting activity of EC19 and EC23, as shown by the increased Caspase-3/7 activities and DNA fragmentation leading to DNA double-strand breaks. This study sheds the light on the possible use of EC-synthetic retinoids in the rescue of multi-drug resistance in colorectal cancer using Caco-2 as a model and suggests new promising combinations between different synthetic retinoids. The current in vitro results pave the way for future studies on these compounds as possible cures for colorectal carcinoma.

Objective: Berberine (BBR) is a known alkaloid that has verified its protective effects against ischemia/reperfusion (I/RN) lesion in multiple organs but its poor oral bioavailability limited its use. Despite the previous works, its possible impact on the warm hepatic I/RN-induced lesion is not clear. Accordingly, a nanostructured lipid carrier of BBR (NLC BBR) was developed for enhancing its efficiency and to inspect its protective mechanistic against warm hepatic I/RN., Methods: NLC BBR formula was evaluated pharmaceutically. Wistar rats were orally pre-treated with either BBR or NLC BBR (100 mg/kg) for 2 weeks followed by hepatic I/RN (30 min/24 h). Biochemical, ELISA, qPCR, western blot, histopathological, and immunohistochemical studies were performed., Key Findings: Optimized NLC BBR was prepared with a particle size of 130 ± 8.3 nm. NLC BBR divulged its aptitude to safeguard the hepatic tissues partly due to anti-inflammatory capacity through downsizing the HMGB1/TLR4/NF-κB trajectory with concomitant rebating of TNF-α, iNOS, COX-2, and MPO content. Furthermore, NLC BBR antiapoptotic trait was confirmed by boosting the prosurvival protein (Bcl-2) and cutting down the pro-apoptotic marker (Bax). Moreover, its antioxidant nature was confirmed by TAC uplifting besides MDA subsiding. On the other hand, NLC BBR action embroiled autophagy flux spiking merit exemplified in Beclin-1 and LC3-II enhancement. Finally, NLC BBR administration ascertained its hepatocyte guarding action by recovering the histopathological ailment and diminishing serum transaminases., Conclusion: NLC BBR purveyed reasonable shielding mechanisms and subsided incidents contemporaneous to warm hepatic I/RN lesion in part, by moderating HMGB1/TLR4/NF-κB inflammatory signaling, autophagy, and apoptosis., (Copyright © 2021 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Objective: Morin (MRN), a known natural flavonol, has demonstrated its shielding aptitude against ischemia/reperfusion (I/Re) lesion in various organs. Nonetheless, its potential influence on hepatic I/Re-induced injury modulation has not been fully elucidated. Consequently, the current study strived to investigate the mechanistic maneuvering of MRN against hepatic I/Re. Furthermore, the effects of MRN on Nrf2, TLR4, and NLRP3 proteins were evaluated via molecular docking studies., Methods: For fulfilling this aim, Sprague-Dawley rats were allotted into 4 groups; Sham-operated (ShG), hepatic I/Re (30 min/24 h), and 10 days orally pre-treated MRN (50 and 100 mg/kg)., Key Findings: MRN mechanistic maneuver disclosed its ability to safeguard the hepatocytes partially due to antioxidant aptitude through intensifying the expression/content of Nrf2/HO-1 trajectory accompanied by total antioxidant capacity boosting besides MDA lessening. In addition, MRN anti-inflammatory attribute was affirmed by downsizing the expression/content of TLR4/NF-κB trajectory accompanied by a sequent lessening of TNF-α, IL-1β, IL-6, and ICAM-1 content. Moreover, MRN action entangled NLRP3 inhibitory character with subsequent MPO rebating. Furthermore, MRN anti-apoptotic trait verified by diminishing the pro-apoptotic and the executioner markers; Bax and caspase-3 levels, respectively. On the other hand, MRN administration proved its shielding action by improving the histopathological deterioration and lessening the serum ALT and AST levels. Finally, in silico studies exhibited moderate to promising binding affinities of MRN with the selected proteins ranging from -4.23 to -6.09 kcal mol -1 ., Conclusion: Higher and lower doses of MRN purveyed plausible defensive mechanisms and abated episodes concomitant with hepatic I/Re mischief in part, by modifying oxidative status and inflammation by the impact on Nrf2/HO-1, TLR4/ NF-κB, and NLRP3 pathway., (Copyright © 2021 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Despite advances in treatment, breast cancer remains the widest spread disease among females with a high mortality rate. We investigated the potential effects of gallic acid (GA) as supportive therapy in the management of breast cancer. Anti-cancer activity with GA alone or in combination with paclitaxel and/or carboplatin was assessed by MTT assay and flow cytometry using annexin V/propidium iodide. The mechanism underlying the antiproliferative effects was investigated by measuring the expression of the pro-apoptotic marker (Bax), CASP-3, anti-apoptotic (Bcl-2), and, tumor suppressor (p53) by real-time polymerase chain reaction (RT-PCR) and western blot analysis. Cell cycle analysis was performed for the MCF-7 breast cancer cell line. GA, paclitaxel, and carboplatin alone or in combination arrested cell cycle progression at the G2/M phase and induced Pre-G1 apoptosis. RT-PCR showed that the triplet combination significantly raised P53, Bax, and CASP-3 mRNA expression (20.1 ± 1.41, 16.6 ± 0.43, and 20.04 ± 1.61, respectively) in MCF-7 cells when compared to single or combined treatment (p < .0001) while anti-apoptotic Bcl-2 mRNA levels were decreased in all treated groups compared to untreated cells. Western blot data of tested apoptotic factors were consistent with RT-PCR results. For the first time, we show that a minimum non-toxic concentration of GA increased the efficacy of paclitaxel- and carboplatin-induced MCF-7 apoptotic cell death., (© 2020 Wiley Periodicals LLC.)

(1) Background and Aim: All- trans retinoic acid (ATRA) induces differentiation and inhibits growth of many cancer cells. However, resistance develops rapidly prompting the urgent need for new synthetic and potent derivatives. EC19 and EC23 are two synthetic retinoids with potent stem cell neuro-differentiation activity. Here, these compounds were screened for their in vitro antiproliferative and cytotoxic activity using an array of different cancer cell lines. (2) Methods: MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, AV/PI (annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI)), cell cycle analysis, immunocytochemistry, gene expression analysis, Western blotting, measurement of glutamate and total antioxidant concentrations were recruited. (3) Results: HepG2, Caco-2, and MCF-7 were the most sensitive cell lines; HepG2 (ATRA; 36.2, EC19; 42.2 and EC23; 0.74 µM), Caco-2 (ATRA; 58.0, EC19; 10.8 and EC23; 14.7 µM) and MCF-7 (ATRA; 99.0, EC19; 9.4 and EC23; 5.56 µM). Caco-2 cells were selected for further biochemical investigations. Isobologram analysis revealed the combined synergistic effects with 5-fluorouracil with substantial reduction in IC 50 . All retinoids induced apoptosis but EC19 had higher potency, with significant cell cycle arrest at subG 0 -G 1 , -S and G 2 /M phases, than ATRA and EC23. Moreover, EC19 reduced cellular metastasis in a transwell invasion assay due to overexpression of E-cadherin, retinoic acid-induced 2 ( RAI2 ) and Werner ( WRN ) genes. (4) Conclusion: The present study suggests that EC-synthetic retinoids, particularly EC19, can be effective, alone or in combinations, for potential anticancer activity to colorectal cancer. Further in vivo studies are recommended to pave the way for clinical applications.

The calcineurin inhibitor, cyclosporin A (CsA) is one of the most common immunosuppressive agents used in organ transplantation. However, its clinical use is often limited by several unwanted effects including nephrotoxicity and hepatotoxicity. By using immunohistochemical and ELISA techniques, it was found that CsA administration causes a rapid activation of a disintegrin and metalloproteases-17 (ADAM-17), epidermal growth factor receptor (EGFR) and subsequent ERK1/2 phosphorylation in the liver and kidney of albino mice. Furthermore, this study presents mechanistic relevance of this signaling cascade involving reactive oxygen species (ROS)-mediated ADAM-17/EGFR/ERK1/2 activation as indicated by a clear reduction in ADAM-17 and EGFR activities as well as ERK1/2 phosphorylation when the animals pretreated with Polyethylene glycol-superoxide dismutase (PEG-SOD) before CsA administration. Collectively, our findings demonstrate that CsA has the ability to activate ADAM-17-mediated EGFR/ERK1/2 phosphorylation in the liver and kidney of albino mice in ROS-dependent manner. Finally, these data may support the concept of using antioxidant therapy as a valuable approach for the prevention of CsA-induced nephrotoxicity and hepatotoxicity., (Copyright © 2020 Elsevier B.V. All rights reserved.)

One of the most common causes of cancer mortality worldwide is hepatocellular carcinoma (HCC). Extracellular signal-regulated kinase (ERK1/2) pathway has been shown to play an important role in the development and progression of HCC. Here, we demonstrate that the immunosuppressive agent cyclosporin A (CsA) has the ability to increase the cellular growth in HCC (HepG2 cells) via activation of ERK1/2 signaling cascade. It was found that ERK1/2 phosphorylation induced by CsA was highly reduced in the presence of the reactive oxygen species (ROS) scavenger polyethylene glycol-superoxide dismutase (PEG-SOD). Furthermore, it was observed that inhibition of metalloproteinase activity using TAPI-2 prevents ERK1/2 activation by CsA. Moreover, a disintegrin and metalloproteinase domain 17 (ADAM-17) activity was found to be critical for ERK phosphorylation by CsA. In addition, CsA-induced ERK phosphorylation was highly reduced in the presence of either neutralizing anti-heparin-binding-epidermal growth factor (HB-EGF) antibody or UO126 (MEK inhibitor). By using the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor AG1478, it was found that EGFR is critical for ERK phosphorylation induced by CsA. Furthermore, CsA-induced cell proliferation was strongly reduced in the presence of either PEG-SOD or TAPI-2 or neutralizing anti-ADAM17 antibody or neutralizing anti-HB-EGF antibody or AG1478 or UO126. Collectively, these data demonstrate that CsA has the ability to activate ERK1/2 signaling cascade that could be translated into an increase in HepG2 cell proliferation. Furthermore, these data support the role of ROS, ADAM-17, and EGFR in ERK1/2 signaling activation and subsequent cell proliferation induced by CsA in HepG2 cells.

Organotypic brain culture is an experimental tool widely used in neuroscience studies. One major drawback of this technique is reduced neuronal survival across time, which is likely exacerbated by the loss of blood flow. We have designed a novel, tube flow system, which is easily incorporated into the commonly-used, standard semi-permeable membrane culture methodology which has significantly enhanced neuronal survival in a brain stem nucleus involved in control of motivated and arousal states: the laterodorsal tegmental nucleus (LDT). Our automated system provides nutrients and removes waste in a comparatively aseptic environment, while preserving temperature, and oxygen levels. Using immunohistochemistry and electrophysiology, our system was found superior to standard techniques in preserving tissue quality and survival of LDT cells for up to 2 weeks. In summary, we provide evidence for the first time that the LDT can be preserved in organotypic slice culture, and further, our technical improvements of adding a flow system, which likely enhanced perfusion to the slice, were associated with enhanced neuronal survival. Our perfusion system is expected to facilitate organotypic experiments focused on chronic stimulations and multielectrode recordings in the LDT, as well as enhance neuronal survival in slice cultures originating from other brain regions.

In the present study, the functional properties of α7 nicotinic acetylcholine receptors (α7 nAChRs) and N-methyl-D-aspartate receptors (NMDARs) endogenously expressed in SH-SY5Y human neuroblastoma cells were characterized in an extracellular-signal regulated kinase (ERK) phosphorylation assay. Both choline and N-methyl-D-aspartate (NMDA) mediated robust concentration-dependent increases in ERK phosphorylation in the SH-SY5Y cells, exhibiting EC 50 values in good agreement with those reported for the agonists at recombinant α7 nAChRs and NMDARs, respectively. Importantly, the responses evoked by choline (10 mM) and by NMDA (50 μM) were significantly inhibited by the α7-selective antagonist α-bungarotoxin (100 nM) and by the NMDAR-selective antagonist MK-801 (50 μM), respectively. The increased ERK phosphorylation levels observed upon co-application of choline (1, 3, 10 mM) and NMDA (50 μM) compared to those produced by the two agonists on their own were fully reconcilable with additive effects and did not reveal substantial synergy between α7 nAChR and NMDAR signaling. Interestingly, however, the responses evoked by the "choline (10 mM) - NMDA (50 μM)" combination were almost completely inhibited by α-bungarotoxin (100 nM) as well as by MK-801 (50 μM), suggesting some sort of a link between α7 nAChR- and NMDAR-mediated ERK phosphorylation. Finally, oligomeric amyloid-β 1-42 peptide (1000 nM) mediated robust inhibition of the ERK phosphorylation induced by choline (10 mM), NMDA (50 μM) and the "choline (10 mM) - NMDA (50 μM)" combination. In conclusion, ERK phosphorylation measurements in SH-SY5Y cells provides a robust assay for studies of α7 nAChR- and NMDAR-mediating signaling and putative functional interactions between the receptors., (Copyright © 2018 Elsevier B.V. All rights reserved.)

α7 nicotinic acetylcholine receptors (nAChRs) and N-methyl-D-aspartate receptors (NMDARs) are key mediators of central cholinergic and glutamatergic neurotransmission, respectively. In addition to numerous well-established functional interactions between α7 nAChRs and NMDARs, the two receptors have been proposed to form a multimeric complex, and in the present study we have investigated this putative α7 nAChR/NMDAR assembly in human and murine brain tissues. By α-bungarotoxin (BGT) affinity purification, α7 and NMDAR subunits were co-purified from human and murine cortical and hippocampal homogenates, substantiating the notion that the receptors are parts of a multimeric complex in the human and rodent brain. Interestingly, the ratios between GluN1 and α7 levels in BGT pull-downs from cortical homogenates from Alzheimer's disease (AD) brains were significantly lower than those in pull-downs from non-AD controls, indicating a reduced degree of α7 nAChR/NMDAR complex formation in the diseased tissue. A similar difference in GluN1/α7 ratios was observed between pull-downs from cortical homogenates from adult 3xTg-AD and age-matched wild type (WT) mice, whereas the GluN1/α7 ratios determined in pull-downs from young 3xTg-AD and age-matched WT mice did not differ significantly. The observation that pretreatment with oligomeric amyloid-β1-42 reduced GluN1/α7 ratios in BGT pull-downs from human cortical homogenate in a concentration-dependent manner provided a plausible molecular mechanism for this observed reduction. In conclusion, while it will be important to further challenge the existence of the putative α7 nAChR/NMDAR complex in future studies applying other methodologies than biochemical assays and to investigate the functional implications of this complex for cholinergic and glutamatergic neurotransmission, this work supports the formation of the complex and presents new insights into its regulation in healthy and diseased brain tissue.