Publications by authors named "Abdelkader Daoud"

14 Publications

  • Page 1 of 1

Generation of human colonic organoids from human pluripotent stem cells.

Methods Cell Biol 2020 8;159:201-227. Epub 2020 Apr 8.

Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, United States. Electronic address:

Advances in human pluripotent stem cell (hPSC) biology now allow the generation of organoids that resemble different regions of the gastrointestinal tract. Generation of region-specific organoids has been facilitated by developmental biology studies carried out in model organisms such as mouse, frog and chick. By mimicking embryonic development, hPSC-derived human colonic organoids (HCOs) can be generated through a stepwise differentiation, first into definitive endoderm (DE), then into mid/hindgut spheroids which are then patterned into posterior gut tissue which gives rise to HCOs following prolonged in vitro culture. HCOs undergo transitions similar to those observed in the developing colon of model organisms and human embryos. HCOs develop into tissue that resembles fetal colon on the basis of morphology, gene expression and presence of differentiated cell types. Generation of HCOs without the proper training or expertise can be a daunting task. Here, we describe a detailed protocol for differentiating hPSCs into HCOs, we include suggestions for troubleshooting these differentiations, and we discuss experimental design considerations. We have also highlighted the key advantages and limitations of the system.
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http://dx.doi.org/10.1016/bs.mcb.2020.03.001DOI Listing
April 2020

Low Dose Cyclophosphamide Modulates Tumor Microenvironment by TGF-β Signaling Pathway.

Int J Mol Sci 2020 Jan 31;21(3). Epub 2020 Jan 31.

State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.

The tumor microenvironment has been recently recognized as a critical contributor to cancer progression and anticancer therapy-resistance. Cyclophosphamide (CTX) is a cytotoxic agent commonly used in clinics for the treatment of cancer. Previous reports demonstrated that CTX given at low continuous doses, known as metronomic schedule, mainly targets endothelial cells and circulating Tregs with unknown mechanisms. Here, we investigated the antitumor activity of two different metronomic schedules of CTX along with their corresponding MTD regimen and further explored their effect on immune function and tumor microenvironment. Toxicity evaluation was monitored by overall survival rate, weight loss, and histopathological analysis. A nude mouse model of Lewis lung cancer was established to assess the anti-metastatic effects of CTX in vivo. CD4, CD8, and CD4CD25FoxP3 T cells were selected by flow cytometry analysis. Low and continuous administration of CTX was able to restore immune function via increase of CD4/CD8 T cells and depletion of T regulatory cells, not only in circulatory and splenic compartments, but also at the tumor site. Low-dose CTX also reduced myofibroblasts, accompanied with an increased level of E-cadherin and low N-cadherin, both in the primary tumor and lung through the TGF-β pathway by the downregulated expression of TGF-β receptor 2. Our data may indicate that several other molecular mechanisms of CTX for tumor may be involved in metronomic chemotherapy, besides targeting angiogenesis and regulatory T cells.
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http://dx.doi.org/10.3390/ijms21030957DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7038197PMC
January 2020

Insights Into Human Development and Disease From Human Pluripotent Stem Cell Derived Intestinal Organoids.

Front Med (Lausanne) 2019 17;6:297. Epub 2019 Dec 17.

Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, United States.

In recent years, advances in human pluripotent stem cell (hPSC) biology have enabled the generation of gastrointestinal (GI) organoids which recapitulate aspects of normal organ development. HPSC derived gastrointestinal organoids are comprised of epithelium and mesenchyme and have a remarkable ability to self-organize and recapitulate early stages of human intestinal development. Furthermore, hPSC derived organoids can be transplanted into immunocompromised mice which allows further maturation of both the epithelium and mesenchyme. In this review, we will briefly summarize work from model systems which has elucidated mechanisms of GI patterning and how these insights have been used to guide the differentiation of hPSCs into organoids resembling small intestine and colon. We will succinctly discuss how developmental principles have been used to promote maturation of human intestinal organoids (HIOs) as well as to introduce an enteric nervous system into HIOs. We will then concisely review how organoids have been used to study human pathogens, how new genetic and bioengineering tools are being applied to organoid research, and how this integration has allowed researchers to elucidate mechanisms of human development and disease. Finally, we will briefly discuss remaining challenges in the field and how they can be addressed. HPSC derived organoids are promising new model systems which hold the potential of unlocking unknown mechanisms of human gastrointestinal development and disease.
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http://dx.doi.org/10.3389/fmed.2019.00297DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6951411PMC
December 2019

Targeting Chromatin Remodeling for Cancer Therapy.

Curr Mol Pharmacol 2019 ;12(3):215-229

Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina, United States.

Background: Epigenetic alterations comprise key regulatory events that dynamically alter gene expression and their deregulation is commonly linked to the pathogenesis of various diseases, including cancer. Unlike DNA mutations, epigenetic alterations involve modifications to proteins and nucleic acids that regulate chromatin structure without affecting the underlying DNA sequence, altering the accessibility of the transcriptional machinery to the DNA, thus modulating gene expression. In cancer cells, this often involves the silencing of tumor suppressor genes or the increased expression of genes involved in oncogenesis. Advances in laboratory medicine have made it possible to map critical epigenetic events, including histone modifications and DNA methylation, on a genome-wide scale. Like the identification of genetic mutations, mapping of changes to the epigenetic landscape has increased our understanding of cancer progression. However, in contrast to irreversible genetic mutations, epigenetic modifications are flexible and dynamic, thereby making them promising therapeutic targets. Ongoing studies are evaluating the use of epigenetic drugs in chemotherapy sensitization and immune system modulation. With the preclinical success of drugs that modify epigenetics, along with the FDA approval of epigenetic drugs including the DNA methyltransferase 1 (DNMT1) inhibitor 5-azacitidine and the histone deacetylase (HDAC) inhibitor vorinostat, there has been a rise in the number of drugs that target epigenetic modulators over recent years.

Conclusion: We provide an overview of epigenetic modulations, particularly those involved in cancer, and discuss the recent advances in drug development that target these chromatin-modifying events, primarily focusing on novel strategies to regulate the epigenome.
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http://dx.doi.org/10.2174/1874467212666190215112915DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6875867PMC
March 2020

A Small β-Carboline Derivative "B-9-3" Modulates TGF-β Signaling Pathway Causing Tumor Regression .

Front Pharmacol 2018 19;9:788. Epub 2018 Jul 19.

State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China.

Targeting tumor microenvironment (TME) is crucial in order to overcome the anti-cancer therapy resistance. In this study, we report the antitumor activity of a newly synthesized β-carboline derivative "B-9-3." Here, this small molecule showed a promising antitumor activity along with an enhanced immune response as reflected by a reduction of regulatory T cells and increased CD4+/CD8+ T cells. Further, B-9-3 decreased the number of myofibroblasts not only in the tumor but also in the lung suggesting an anti-metastatic action. The reduction of myofibroblasts was associated with lower expression of epithelial-to-mesenchymal transition markers and a decrease of phosphorylated SMAD2/3 complex indicating the implication of TGF-β signaling pathway in B-9-3's effect. The blockade of myofibroblasts induction by B-9-3 was also verified in human fibroblasts treated with TGF-β. To elucidate the mechanism of B-9-3's action on TGF-β pathway, first, we investigated the molecular interaction between B-9-3 and TGF-β receptors using docking method. Data showed a weak interaction of B-9-3 with the ATP-binding pocket of TGFβRI but a strong one with a ternary complex formed of extracellular domains of TGFβRI, TGFβRII, and TGF-β. In addition, the role of TGFβRI and TGFβRII in B-9-3's activity was explored . B-9-3 did not decrease any of the two receptors' protein level and only reduced phosphorylated SMAD2/3 suggesting that its effect was more probably due to its interaction with the ternary complex rather than decreasing the expression of TGF-β receptors or interfering with their ATP-binding domains. B-9-3 is a small active molecule which acts on the TGF-β signaling pathway and improves the TME to inhibit the proliferation and the metastasis of the tumor with the potential for clinical application.
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http://dx.doi.org/10.3389/fphar.2018.00788DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6063040PMC
July 2018

Molecular and functional crosstalk between extracellular Hsp90 and ephrin A1 signaling.

Oncotarget 2017 Dec 3;8(63):106807-106819. Epub 2017 Nov 3.

Department of Cell and Molecular Pharmacology, Medical University of South Carolina, SC, 29412, Charleston, USA.

The Eph receptor tyrosine kinase family member EphA2 plays a pivotal role in modulating cytoskeletal dynamics to control cancer cell motility and invasion. EphA2 is frequently upregulated in diverse solid tumors and has emerged as a viable druggable target. We previously reported that extracellular Hsp90 (eHsp90), a known pro-motility and invasive factor, collaborates with EphA2 to regulate tumor invasion in the absence of its cognate ephrin ligand. Here, we aimed to further define the molecular and functional relationship between EphA2 and eHsp90. Ligand dependent ephrin A1 signaling promotes RhoA activation and altered cell morphology to favor transient cell rounding, retraction, and diminished adhesion. Exposure of EphA2-expressing cancer cells to ligand herein revealed a unique role for eHsp90 as an effector of cytoskeletal remodeling. Notably, blockade of eHsp90 via either neutralizing antibodies or administration of cell-impermeable Hsp90-targeted small molecules significantly attenuated ligand dependent cell rounding in diverse tumor types. Although eHsp90 blockade did not appear to influence receptor internalization, downstream signaling events were augmented. In particular, eHsp90 activated a Src-RhoA axis to enhance ligand dependent cell rounding, retraction, and ECM detachment. Moreover, eHsp90 signaling via this axis stimulated activation of the myosin pathway, culminating in formation of an EphA2-myosin complex. Inhibition of either eHsp90 or Src was sufficient to impair ephrin A1 mediated Rho activation, activation of myosin intermediates, and EphA2-myosin complex formation. Collectively, our data support a paradigm whereby eHsp90 and EphA2 exhibit molecular crosstalk and functional cooperation within a ligand dependent context to orchestrate cytoskeletal events controlling cell morphology and attachment.
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http://dx.doi.org/10.18632/oncotarget.22370DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5739775PMC
December 2017

β-elemene inhibits monocyte-endothelial cells interactions via reactive oxygen species/MAPK/NF-κB signaling pathway in vitro.

Eur J Pharmacol 2015 Nov 28;766:37-45. Epub 2015 Sep 28.

National Center for Drug Screening & State Key Laboratory of Natural Medicines, China Pharmaceutical University, Jiangsu Province 210009, PR China; Jiangsu Key Laboratory of TCM Evaluation and Translational Research, China Pharmaceutical University, 24 Tong jia xiang, Nanjing 210009, Jiang Su Province, PR China. Electronic address:

The recruitment of monocytes to the active endothelial cells is an early step in the formation of atherosclerotic lesions; therefore, the inhibition of monocyte-endothelial cells interactions may serve as a potential therapeutic strategy for atherosclerosis. Recent studies suggest that β-elemene can protect against atherosclerosis in vivo and vitro; however, the mechanism underlying the anti-atherosclerotic effect by β-elemene is not clear yet. In this study, we aimed to investigate the effects of β-elemene on the monocyte-endothelial cells interactions in the initiation of atherosclerosis in vitro. Our results showed that β-elemene protects human umbilical vein endothelial cells (HUVECs) from hydrogen peroxide-induced endothelial cells injury in vitro. Besides, this molecule inhibits monocyte adhesion and transendothelial migration across inflamed endothelium through the suppression of the nuclear factor-kappa B-dependent expression of cell adhesion molecules. Further, β-elemene decreases generation of reactive oxygen species (ROS) and prevents the activation of mitogen-activated protein kinase (MAPK) signaling pathway in HUVECs. In conclusion, this study would provide a new pharmacological evidence of the significance of β-elemene as a future drug for prevention and treatment of atherosclerosis.
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http://dx.doi.org/10.1016/j.ejphar.2015.09.032DOI Listing
November 2015

Corrigendum to "reduced oxidative stress contributes to the lipid lowering effects of isoquercitrin in free fatty acids induced hepatocytes".

Oxid Med Cell Longev 2015 23;2015:383525. Epub 2015 Mar 23.

National Center for Drug Screening and State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjiaxiang, Nanjing, Jiangsu 210009, China.

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http://dx.doi.org/10.1155/2015/383525DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4412213PMC
September 2015

Combination therapy with oleanolic acid and metformin as a synergistic treatment for diabetes.

J Diabetes Res 2015 18;2015:973287. Epub 2015 Feb 18.

National Drug Screening Center and Jiangsu Key Laboratory of TCM Evaluation and Translational Research, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China.

Aims And Background: Type 2 diabetes is a chronic disease that cannot be treated adequately using the known monotherapies, especially when the disease progresses to an advanced stage. In this study, we explore the possibility of treating the disease with a novel combination approach of oleanolic acid (OA), a glycogen phosphorylase (GP) inhibitor, and metformin.

Methods: Db/db mice were randomly divided into four groups: a db/db control group, db/db mice treated with OA (250 mg/kg), db/db mice treated with metformin (100 mg/kg), and db/db mice treated with a combination of OA and metformin. All mice were treated for four weeks. The effects of the treatments on glucose homeostasis were measured using an OGTT, an assessment of insulin sensitivity and signaling in the liver, and the hepatic glucose production.

Results: Combination therapy with OA and metformin significantly reduced the blood glucose and insulin levels and improved the liver pathology compared with that for the monotherapy in the db/db diabetic mouse model. We also found that the combination therapy significantly increased the mRNA expression of glycogen synthesis and decreased the GP, PGC-1α, PEPCK1, and G-6-Pase levels. In addition, the combination therapy with OA and metformin significantly increased the phosphorylation of AKT, PI3K, AMPK, and ACC and decreased the protein expression levels of G-6-Pase, PEPCK1, and TORC compared with those for either monotherapy. The combination therapy also reduced the phosphorylation of mTOR and CREB.

Conclusions: Our results suggest that the combination therapy with OA and metformin has synergistic effects on the symptoms of db/db diabetic mice by improving glucose and insulin homeostasis.
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http://dx.doi.org/10.1155/2015/973287DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4350965PMC
December 2015

Reduced oxidative stress contributes to the lipid lowering effects of isoquercitrin in free fatty acids induced hepatocytes.

Oxid Med Cell Longev 2014 22;2014:313602. Epub 2014 Oct 22.

National Center for Drug Screening and State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjiaxiang, Nanjing, Jiangsu 210009, China.

Oxidative stress interferes with hepatic lipid metabolism at various levels ranging from benign lipid storage to so-called second hit of inflammation activation. Isoquercitrin (IQ) is widely present flavonoid but its effects on hepatic lipid metabolism remain unknown. We used free fatty acids (FFA) induced lipid overload and oxidative stress model in two types of liver cells and measured cell viability, intracellular lipids, and reactive oxygen species (ROS) within hepatocytes. In addition, Intracellular triglycerides (TG), superoxide dismutase (SOD), and malondialdehyde (MDA) were examined. A novel in vitro model was used to evaluate correlation between lipid lowering and antioxidative activities. Furthermore, 34 major cytokines and corresponding ROS levels were analyzed in FFA/LPS induced coculture model between hepatocytes and Kupffer cells. At molecular level AMPK pathway was elucidated. We showed that IQ attenuated FFA induced lipid overload and ROS within hepatocytes. Further, IQ reversed FFA induced increase in intracellular TG SOD and MDA. It was shown that antioxidative activity of IQ correlates with its lipid lowering potentials. IQ reversed major proinflammatory cytokines and oxidative stress in FFA/LPS induced coculture model. Finally, AMPK pathway was found responsible for metabolic benefits at molecular level. IQ strikingly manifests antioxidative and related lipid lowering activities in hepatocytes.
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http://dx.doi.org/10.1155/2014/313602DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4227458PMC
June 2015

B-9-3, a novel β-carboline derivative exhibits anti-cancer activity via induction of apoptosis and inhibition of cell migration in vitro.

Eur J Pharmacol 2014 Feb 28;724:219-30. Epub 2013 Dec 28.

New Drug Screening Center, China Pharmaceutical University, 24 Tongjia Road, Nanjing 210009, PR China; State Key Laboratory of Natural Medicines, China Pharmaceutical University, China. Electronic address:

Peganum harmala L is an important medicinal plant that has been used from ancient time due to its alkaloids rich of ß-carbolines. Harmane is a naturally occurring ß-carboline extracted from Peganum harmala L, that exhibits a wide range of biological, psychopharmacological, and toxicological actions. The synthesis of novel derivatives with high anti-cancer activity and less side effects is necessary. In the present study, B-9-3-a semi-synthetic compound that is formed of two harmane molecules bound by a butyl group-showed a strong anti-cancer activity against a human lung cancer cell line, a human breast cancer cell line, and a human colorectal carcinoma cell line. B-9-3 anti-proliferative effect followed a similar pattern in the three cell lines. This pattern includes a dose-dependent induction of apoptosis, or necroptosis as confirmed by Hoechst staining, flow cytometry and western blot analyses, and the inhibition of cancer cells migration that was shown to be dependent on the drug׳s concentration as well. Moreover, B-9-3 inhibited tube formation in human umbilical vascular endothelial cell line (HUVEC), which indicates an anti-angiogenesis activity in vitro. In summary, B-9-3, a semi-synthetic derivative of ß-carboline, has an anti-proliferative effect against tumor cells via induction of apoptosis and inhibition of cell migration.
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http://dx.doi.org/10.1016/j.ejphar.2013.12.038DOI Listing
February 2014

Adipokines and hepatic insulin resistance.

J Diabetes Res 2013 16;2013:170532. Epub 2013 May 16.

National Center for Drug Screening and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Jiangsu Province, China.

Obesity is a major risk factor for insulin resistance and type 2 diabetes. Adipose tissue is now considered to be an active endocrine organ that secretes various adipokines such as adiponectin, leptin, resistin, tumour necrosis factor-α, and interleukin-6. Recent studies have shown that these factors might provide a molecular link between increased adiposity and impaired insulin sensitivity. Since hepatic insulin resistance plays the key role in the whole body insulin resistance, clarification of the regulatory processes about hepatic insulin resistance by adipokines in rodents and human would seem essential in order to understand the mechanism of type 2 diabetes and for developing novel therapeutic strategies to treat it.
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http://dx.doi.org/10.1155/2013/170532DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3670576PMC
January 2014

[Study on material basis of Dracocephalum moldavica for protecting cardiomyocyte against hypoxia/reoxygenation injury by traditional Chinese medicine serum chemical and pharmacological methods].

Zhongguo Zhong Yao Za Zhi 2012 Mar;37(5):620-4

New Drug Screening Center, China Pharmaceutical University, Nanjing 210009, China.

Objective: To study the material basis of Dracocephalum moldavica for protecting cardiomyocyte against hypoxia/ reoxygenation injury by using traditional Chinese medicine (TCM) serum chemical and pharmacological methods.

Method: The extract of D. moldavica (DME) and its content absorbed into blood were determined, while blank serum and medicinal serum of rats before and after intragastrical administration of DME were also compared by HPLC. The Na2S2O4 or N2-based hypoxia/reoxygenation injury model was established by cultivating primary neonate rat cardiomyocytes or H9c2 cells in vitro. Cell viability, LDH release, T-SOD activity, MDA production and apoptosis were detected to learn the effect of DME, medicated serum and different treatments of medicinal serums under different dosage and action duration of DME on cardiomyocyte against hypoxia/reoxygenation injury.

Result: Four transitional components of DME absorbed into blood after intragastrical administration were found, three of which were original components and one possible metabolite. Furthermore, compared with the model group or the blank serum group, LDH release and MDA production (P < 0.05, P < 0.01) of DME extracts, medicated serum or different treatments of medicinal serum under different dosage and action duration of DME. However, T-SOD and cell viability were improved significantly (P < 0.05, P < 0.01), while apoptosis of cardiomyocytes were also obviously inhibited.

Conclusion: The four components absorbed into blood are probably the material basis of DME used for protecting cardiomyocyte agastin hypoxia/reoxygenation injury.
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March 2012

Effects of bpV(pic) and bpV(phen) on H9c2 cardiomyoblasts during both hypoxia/reoxygenation and H2O2-induced injuries.

Mol Med Rep 2012 Mar 22;5(3):852-8. Epub 2011 Dec 22.

New Drug Screening Center, China Pharmaceutical University, Nanjing, Jiangsu 210009, PR China.

Reactive oxygen species (ROS) are involved in myocardial injury. ROS are known to inactivate lipid phosphatase and tension homolog on chromosome 10 (PTEN), an enzyme that increases apoptosis in neonatal cardiomyocytes. BpV(pic) and bpV(phen), two bisperoxovanadium molecules and PTEN inhibitors, may be involved in limiting myocardial infarction. To compare the protective effects of bpV(pic) and bpV(phen) on ROS-induced cardiomyocyte injury and their possible mechanisms, we selected two popular models of hypoxia/reoxygenation (H/R) and H2O2-induced injury in H9c2 cardiomyoblasts to investigate their effects against injury. We found that pre-treatment with bpV(pic) and bpV(phen) increased the viability and protected the morphology of H9c2 cells under the conditions of H/R and H2O2 by inhibiting LDH release, apoptosis and caspases 3/8/9 activities. However, their respective inhibitory abilities in the two models were different, suggesting that the quantity of ROS from the two models might be different. However, the conflict between ROS and PTEN may affect the action of bpV(pic) and bpV(phen). Taken together, the results demonstrate that bpV(pic) and bpV(phen) have inhibitory effects on oxidative stress-induced cardiomyocyte injury that may be partially modulated by the action of ROS on PTEN.
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http://dx.doi.org/10.3892/mmr.2011.737DOI Listing
March 2012