PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7645

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  • Review
    Citation - Scopus: 121
    Natural and Synthetic Nanovectors for Cancer Therapy
    (Ivyspring International Publisher, 2023) Eftekhari, Aziz; Kryschi, Carola; Pamies, David; Ahmadian, Elham; Janas, Dawid; Davaran, Soodabeh; Khalilov, Rovshan; Güleç, Şükrü
    Nanomaterials have been extensively studied in cancer therapy as vectors that may improve drug delivery. Such vectors not only bring numerous advantages such as stability, biocompatibility, and cellular uptake but have also been shown to overcome some cancer-related resistances. Nanocarrier can deliver the drug more precisely to the specific organ while improving its pharmacokinetics, thereby avoiding secondary adverse effects on the not target tissue. Between these nanovectors, diverse material types can be discerned, such as liposomes, dendrimers, carbon nanostructures, nanoparticles, nanowires, etc., each of which offers different opportunities for cancer therapy. In this review, a broad spectrum of nanovectors is analyzed for application in multimodal cancer therapy and diagnostics in terms of mode of action and pharmacokinetics. Advantages and inconveniences of promising nanovectors, including gold nanostructures, SPIONs, semiconducting quantum dots, various nanostructures, phospholipid-based liposomes, dendrimers, polymeric micelles, extracellular and exome vesicles are summarized. The article is concluded with a future outlook on this promising field. © The author(s).
  • Article
    Citation - WoS: 307
    Citation - Scopus: 364
    Iron Absorption: Factors, Limitations, and Improvement Methods
    (American Chemical Society, 2022) Pişkin, Elif; Cianciosi, Danila; Güleç, Şükrü; Tomas, Merve; Çapanoğlu, Esra
    Iron is an essential element for human life since it participates in many functions in the human body, including oxygen transport, immunity, cell division and differentiation, and energy metabolism. Iron homeostasis is mainly controlled by intestinal absorption because iron does not have active excretory mechanisms for humans. Thus, efficient intestinal iron bioavailability is essential to reduce the risk of iron deficiency anemia. There are two forms of iron, heme and nonheme, found in foods. The average daily dietary iron intake is 10 to 15 mg in humans since only 1 to 2 mg is absorbed through the intestinal system. Nutrient-nutrient interactions may play a role in dietary intestinal iron absorption. Dietary inhibitors such as calcium, phytates, polyphenols and enhancers such as ascorbic acid and proteins mainly influence iron bioavailability. Numerous studies have been carried out for years to enhance iron bioavailability and combat iron deficiency. In addition to traditional methods, innovative techniques are being developed day by day to enhance iron bioavailability. This review will provide information about iron bioavailability, factors affecting absorption, iron deficiency, and recent studies on improving iron bioavailability.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    Effects of Golden Thistle (scolymus Hispanicus L.) on Cytotoxic Activity: Cell Cycle Arrest and Apoptotic Properties on the Caco-2 Cell Line
    (Mary Ann Liebert Inc., 2022) Özel Taşcı, Cansu; Güleç, Şükrü
    Cancer is a global concern for many individuals with high mortality rates, with colon cancer being the third most common diagnosed cancer worldwide. A phytochemical-rich diet is often recommended in the prevention and during the treatment of cancer cases. Golden thistle (GT) plant (Scolymus hispanicus L.) is a wild edible plant widely consumed in the Mediterranean countries. In this study, we aimed to obtain a hydromethanolic extract from three parts of the GT plant and test its antiproliferative activity in the CaCo-2 human adenocarcinoma cell line. Concentrations of the golden thistle extract (GTE) were used to treat CaCo-2 cells and the most significant reduction was detected with 4 mg/mL GTE after 72 h, with 78.3% decrease in cell viability (P < .05). Additionally, 4 mg/mL GTE caused 7.8-fold higher release of lactate dehydrogenase enzyme, indicating cell death after treatment. Flow cytometric analyses concluded both 3.3-fold higher early and late apoptotic activity of the 4 mg/mL GTE compared with the nontreated control group (P < .05). Last, 4 mg/mL GTE showed 24.1% reduction in the G1 phase and 38.1% increase in the S phase of cell cycle distribution. The alteration of G1 and S phases in the cell cycle led to growth reduction of CaCo-2 cells and caused apoptosis. Copyright
  • Article
    Citation - WoS: 18
    Citation - Scopus: 19
    Intestinal Hephaestin Potentiates Iron Absorption in Weanling, Adult, and Pregnant Mice Under Physiological Conditions
    (American Society of Hematology, 2017) Doğuer, Çağlar; Ha, Jung-Heun; Güleç, Şükrü; Vulpe, Chris D.; Anderson, Gregory J.; Collins, James F.
    Regulation of intestinal iron absorption is crucial to maintain body iron levels because humans have no regulated iron-excretory system. Elucidating molecular events that mediate intestinal iron transport is thus important for the development of therapeutic approaches to modify iron absorption in pathological states. The process of iron uptake into duodenal enterocytes is relatively well understood, but less is known about the functional coupling between the iron exporter ferroportin 1 and the basolateral membrane iron oxidase hephaestin (Heph). Initial characterization of intestine-specific Heph knockout (Heph(int)) mice demonstrated that adult male mice were mildly iron deficient; however, the specific role of intestinal Heph has not been determined in weanling mice, in female mice, or during physiological states which stimulate iron absorption. Furthermore, because ferroportin 1-mediated iron export from some tissues (eg, liver) is impaired in the absence of the Heph homolog, ceruloplasmin, we hypothesized that Heph is rate limiting for intestinal iron absorption, especially when iron demands increase. Our experimental approach was to assess various physiological parameters and iron (Fe-59) absorption and tissue distribution in weanling, adult, and pregnant Hephint mice (and controls) under physiological conditions and in adult Hephint mice after dietary iron deprivation or acute hemolysis. Results demonstrate that intestinal Heph is essential for optimal iron transport in weanlings and adults of both sexes and during pregnancy, but not in adult mice with iron-deficiency or hemolytic anemia. Moreover, activation of unidentified, intestinal ferroxidases was noted, which may explain why intestinal Heph is not always required for optimal iron absorption.
  • Article
    Citation - WoS: 20
    Citation - Scopus: 20
    The Development of Lentil Derived Protein-Iron Complexes and Their Effects on Iron Deficiency Anemia in Vitro
    (Royal Society of Chemistry, 2020) Evcan, Ezgi; Güleç, Şükrü
    Iron deficiency anemia (IDA) is the most common nutrient-dependent health problem in the world and could be reversed by commercially available iron supplementation. The form of iron supplement is important due to its toxicity on the gastrointestinal system (GI), so the development of new dietary strategies might be important for the prevention of IDA. It has been shown that plant-based proteins bind to iron and might decrease the free form of iron before absorption and increase iron bioavailability. Thus, we aimed to form lentil derived protein-iron complexes and to test the functional properties of hydrolysed protein-iron complexes in anemic Caco-2 cell line. Our main findings were that (i) lentil derived proteins had the capacity to chelate iron minerals and (ii) hydrolysed protein-iron complexes significantly reduced the mRNA levels of iron regulated divalent metal transporter-1 (DMT1), transferrin receptor (TFR), and ankyrin repeat domain 37 (ANKRD37) marker genes that were induced by iron deficiency anemia. The current findings suggest that hydrolysed protein-iron complexes might have functional properties in iron deficiency anemia in vitro. Further in vivo studies are necessary to show lentil derived proteins and iron might be used as supplements or food additives to reduce the risk of iron deficiency anemia.
  • Article
    Citation - WoS: 21
    Citation - Scopus: 21
    Investigation of the Influence of High Glucose on Molecular and Genetic Responses: an in Vitro Study Using a Human Intestine Model
    (BioMed Central Ltd., 2018) Boztepe, Tuğçe; Güleç, Şükrü
    Background: Dietary glucose consumption has increased worldwide. Long-term high glucose intake contributes to the development of obesity and type 2 diabetes mellitus (T2DM). Obese people tend to eat glucose-containing foods, which can lead to an addiction to glucose, increased glucose levels in the blood and intestine lumen, and exposure of intestinal enterocytes to high dietary glucose. Recent studies have documented a role for enterocytes in glucose sensing. However, the molecular and genetic relationship between high glucose levels and intestinal enterocytes has not been determined. We aimed to identify relevant target genes and molecular pathways regulated by high glucose in a well-established in vitro epithelial cell culture model of the human intestinal system (Caco-2 cells). Methods: Cells were grown in a medium containing 5.5 and 25 mM glucose in a bicameral culture system for 21 days to mimic the human intestine. Transepithelial electrical resistance was used to control monolayer formation and polarization of the cells. Total RNA was isolated, and genome-wide mRNA expression profiles were determined. Molecular pathways were analyzed using the DAVID bioinformatics program. Gene expression levels were confirmed by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Results: Microarray gene expression data demonstrated that 679 genes (297 upregulated, 382 downregulated) were affected by high glucose treatment. Bioinformatics analysis indicated that intracellular protein export (p=0.0069) and ubiquitin-mediated proteolysis (p=0.024) pathways were induced, whereas glycolysis/gluconeogenesis (p<0.0001), pentose phosphate (p=0.0043), and fructose-mannose metabolism (p=0.013) pathways were downregulated, in response to high glucose. Microarray analysis of gene expression showed that high glucose significantly induced mRNA expression levels of thioredoxin-interacting protein (TXNIP, p=0.0001) and lipocalin 15 (LCN15, p=0.0016) and reduced those of ATP-binding cassette, sub-family A member 1 (ABCA1, p=0.0004), and iroquois homeobox 3 (IRX3, p=0.0001). Conclusions: To our knowledge, this is the first investigation of high glucose-regulated molecular responses in an intestinal enterocyte model. Our findings identify new target genes that may be important in the intestinal glucose absorption and metabolism during high glucose consumption.
  • Article
    Citation - WoS: 7
    Citation - Scopus: 7
    Ankaferd Influences Mrna Expression of Iron-Regulated Genes During Iron-Deficiency Anemia
    (SAGE Publications Inc., 2018) Güleç, Afife; Güleç, Şükrü
    Ankaferd Blood Stopper (ABS) comprises a mixture of plants and stops bleeding via forming a protein network by erythroid aggregation. Bleeding causes reduction of iron levels in body. It has been indicated that ABS contains significant amount of iron. Thus, we investigated the biological activity of ABS-derived iron on iron-regulated genes during iron-deficiency anemia (IDA). IDA We selected Caco-2 and HepG2 cell lines as in vitro models of human intestine and liver, respectively. Iron deficiency anemia was induced by deferoxamine. The cells were treated with ferric ammonium citrate (FAC) and ABS. Messenger RNA levels of iron-regulated genes were analyzed by quantitative reverse transcription polymerase chain reaction to elucidate whether iron in ABS behaved similar to inorganic iron (FAC) during IDA. The results showed that ABS-derived iron influenced transcriptions of iron-regulated marker genes, including divalent metal transporter (Dmt1), transferrin receptor (TfR), ankyrin repeat domain 37 (Ankrd37), and hepcidin (Hamp) in IDA-induced Caco-2 and HepG2 cells. Our results suggest that when ABS is used to stop tissue bleeding, it might have an ability to reduce levels of IDA.