scholarly journals Nfe2l1-silenced insulinoma cells acquire aggressiveness and chemoresistance

2018 ◽  
Vol 25 (3) ◽  
pp. 185-200 ◽  
Author(s):  
Jingqi Fu ◽  
Hongzhi Zheng ◽  
Qi Cui ◽  
Chengjie Chen ◽  
Simeng Bao ◽  
...  
Keyword(s):  
Antioxidant Response ◽  
Endocrine Tumors ◽  
Mitochondrial Potential ◽  
Allograft Transplantation ◽  
Pancreatic Endocrine Tumors ◽  
Altered Glucose ◽  
Insulinoma Cells ◽  
Transplantation Model

The transcription factor nuclear factor erythroid 2-like 1 (NFE2L1 or NRF1) is involved in various critical cell processes such as maintenance of ubiquitin-proteasome system and regulation of the cellular antioxidant response. We previously determined that pancreatic β-cell-specific Nfe2l1-knockout mice had hyperinsulinemia and that silencing of Nfe2l1 in mouse islets or MIN6 insulinoma β-cells induced elevated basal insulin release and altered glucose metabolism. Hypoglycemia is a major issue with aggressive insulinomas, although a role of NFE2L1 in this pathology is not defined. In the present work, we studied the tumorigenicity of Nfe2l1-deficient insulinoma MIN6 cells (Nfe2l1-KD) and sensitivity to chemotherapy. Nfe2l1-KD cells grew faster and were more aggressive than Scramble cells in vitro. In a mouse allograft transplantation model, insulinomas arising from Nfe2l1-KD cells were more aggressive and chemoresistant. The conclusion was amplified using streptozotocin (STZ) administration in an allograft transplantation model in diabetic Akita background mice. Furthermore, Nfe2l1-KD cells were resistant to damage by the chemotherapeutic drugs STZ and 5-fluorouracil, which was linked to binding of hexokinase 1 with mitochondria, enhanced mitochondrial membrane potential and closed mitochondrial potential transition pore. Overall, both in vitro and in vivo data from Nfe2l1-KD insulinoma cells provided evidence of a previously un-appreciated action of NFE2L1 in suppression of tumorigenesis. Nfe2l1 silencing desensitizes insulinoma cells and derived tumors to chemotherapeutic-induced damage, likely via metabolic reprograming. These data indicate that NFE2L1 could potentially play an important role in the carcinogenic process and impact chemosensitivity, at least within a subset of pancreatic endocrine tumors.

Targeting PPARalpha in Alzheimer's Disease

2018 ◽  
Vol 15 (4) ◽  
pp. 345-354 ◽  
Author(s):  
Barbara D'Orio ◽  
Anna Fracassi ◽  
Maria Paola Cerù ◽  
Sandra Moreno
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Molecular Mechanisms ◽  
Redox Homeostasis ◽  
Antioxidant Response ◽  
Peroxisome Proliferator ◽  
Prevailing Paradigm

Background: The molecular mechanisms underlying Alzheimer's disease (AD) are yet to be fully elucidated. The so-called “amyloid cascade hypothesis” has long been the prevailing paradigm for causation of disease, and is today being revisited in relation to other pathogenic pathways, such as oxidative stress, neuroinflammation and energy dysmetabolism. The peroxisome proliferator-activated receptors (PPARs) are expressed in the central nervous system (CNS) and regulate many physiological processes, such as energy metabolism, neurotransmission, redox homeostasis, autophagy and cell cycle. Among the three isotypes (α, β/δ, γ), PPARγ role is the most extensively studied, while information on α and β/δ are still scanty. However, recent in vitro and in vivo evidence point to PPARα as a promising therapeutic target in AD. Conclusion: This review provides an update on this topic, focussing on the effects of natural or synthetic agonists in modulating pathogenetic mechanisms at AD onset and during its progression. Ligandactivated PPARα inihibits amyloidogenic pathway, Tau hyperphosphorylation and neuroinflammation. Concomitantly, the receptor elicits an enzymatic antioxidant response to oxidative stress, ameliorates glucose and lipid dysmetabolism, and stimulates autophagy.

scholarly journals Induction of the Protective Antioxidant Response Element Pathway by 6-Hydroxydopamine In Vivo and In Vitro

2005 ◽  
Vol 87 (1) ◽  
pp. 176-186 ◽  
Author(s):  
Rebekah J. Jakel ◽  
Jonathan T. Kern ◽  
Delinda A. Johnson ◽  
Jeffrey A. Johnson
Keyword(s):  
Antioxidant Response ◽  
Antioxidant Response Element ◽  
Response Element ◽  
6 Hydroxydopamine

scholarly journals Сhanges in intracellular calcium concentration and mitochondrial potential in primary cultures of rat brain cells in acute mechanical injury

2018 ◽  
pp. 124-128
Author(s):  
И.А. Красильникова ◽  
З.В. Бакаева ◽  
В.Г. Пинелис ◽  
О.Ю. Лисина ◽  
А.М. Сурин
Keyword(s):  
Calcium Concentration ◽  
Primary Cultures ◽  
Mechanical Injury ◽  
Ionotropic Glutamate Receptors ◽  
Mitochondrial Potential ◽  
Microscopy Technique ◽  
Nmda Channels ◽  
Old Rats

Актуальность. Моделирование in vitro травматического повреждения мозга помогает выяснить патологические механизмы, ответственные за гибель клеток или их последующую дисфункцию в деталях, труднодостижимых in vivo. Цель. Определить изменения внутриклеточной концентрации свободного Са2+ ([Ca2+]i) и митохондриального потенциала (m) в первичной нейроглиальной культуре непосредственно в момент нанесения механической травмы. Методы и материалы. Методом флуоресцентной микроскопии отслеживали изменения [Ca2+]i) и m в первичной нейроглиальной культуре из коры головного мозга 1-2-дневных крыс. Возраст культуры в момент измерений 11-14 дней. Результаты. Обнаружено, что нейротравма вызывает скачок [Ca2+]i и совпадающее с ним по времени резкое падение m. Эти изменения затрагивали клетки, расположенные не далее 100мкм от границы травмы. Блокирование ионотропных глутаматных рецепторов NMDA-типа с помощью МК-801 снижало в 8,5 раз долю нейронов, имевших высокий подъем [Ca2+]i. Выводы. Поступления Са2+ в клетки при механическом повреждении первичной нейроглиальной культуры происходит преимущественно по NMDA-каналам и отчасти, вероятно, по АТФ-активируемым каналам. Background. In vitro modeling of traumatic brain injury helps clarifying pathological mechanisms responsible for cell death or their subsequent dysfunction in detail, which is difficult to accomplish in vivo. Aim. To determine changes in intracellular free Ca2+ concentration ([Ca2+]i) and mitochondrial potential (m) in a primary neuroglial culture during infliction of a mechanical injury (scratch). Methods and materials. Changes in [Ca2+]i and m in the primary neuroglial culture from the cerebral cortex of 1-2 day old rats were monitored using a fluorescence microscopy technique. Measurements were performed in 11-14-day old cultures. Results. Neurotrauma resulted in a sharp increase in [Ca2+]i and a synchronous profound drop of m. These changes affected cells located not farther than 100 µm from the boundary of the injury. Inhibition of NMDA-type ionotropic glutamate receptors with MK-801 reduced by approximately 8.5 times the proportion of neurons, which indicated a high [Ca2+]i rise. Conclusion. Са2+ influx into cells during mechanical injury of the primary neuroglial culture occurs predominantly through NMDA-channels and perhaps partially through ATP-activated channels.

scholarly journals Combinatorial Treatment with mTOR Inhibitors and Streptozotocin Leads to Synergistic In Vitro and In Vivo Antitumor Effects in Insulinoma Cells

2017 ◽  
Vol 17 (1) ◽  
pp. 60-72 ◽  
Author(s):  
Julien Bollard ◽  
Céline Patte ◽  
Patrick Massoma ◽  
Isabelle Goddard ◽  
Nicolas Gadot ◽  
...  
Keyword(s):  
Mtor Inhibitors ◽  
Antitumor Effects ◽  
Insulinoma Cells ◽  
Combinatorial Treatment

Antineoplastic Activity of Products Derived From Cellulose-containing Materials: Study of Levoglucosenone and Structurally-related Analogous as New Alternatives for Breast Cancer Treatment

2021 ◽  
Author(s):  
Damian Ignacio Delbart ◽  
German Francisco Giri ◽  
Agostina Cammarata ◽  
Lizeth Ariza Bareño ◽  
Natalia Loreley Amigo ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Treatment ◽  
Breast Cancer Treatment ◽  
Soybean Hulls ◽  
Mitochondrial Potential ◽  
Cell Content ◽  
Lung Colonization ◽  
Ethidium Bromide Staining

Abstract Purpose: Breast cancer is the leading cause of cancer death among women worldwide. For this reason, the development of new therapies is still essential. In this work we have analyzed the antitumor potential of levoglucosenone, a chiral building block derived from glucose, and three structurally related analogues obtained from soybean hulls pyrolysis.Methods: Employing human and murine mammary cancer models, we have evaluated the effect of our compounds on cell viability through MTS assay, apoptosis induction by acridine orange / ethidium bromide staining and/or flow cytometry and the loss of mitochondrial potential by tetramethylrhodamine methyl ester staining. Autophagy and senescence induction were also evaluated by Western blot and β-galactosidase activity respectively. Secreted metalloproteases activity was determined by quantitative zymography. Migratory capacity was assessed by wound healing assays while invasive potential was analyzed using Matrigel-coated transwell chambers. In vivo studies were also performed to evaluate subcutaneous tumor growth and experimental lung colonization.Results: Apoptosis was identified as the main mechanism responsible for the reduction of monolayer cell content induced by the compounds without detecting modulations of autophagy or senescence processes. Two of the four compounds were able to modulate in vitro events associated with tumor progression, such as migratory potential, invasiveness, and proteases secretion. Furthermore, tumor volume and metastatic spread were significantly reduced in vivo after treatment with the compounds.Conclusion: We could obtain from soybean hulls, a material with almost no commercial value, a variety of chemical compounds useful for breast cancer treatment.

CD40 inhibits B cell apoptosis by upregulating bcl-xL expression and blocking oxidant accumulation

1997 ◽  
Vol 272 (3) ◽  
pp. C950-C956 ◽  
Author(s):  
W. Fang ◽  
K. A. Nath ◽  
M. F. Mackey ◽  
R. J. Noelle ◽  
D. L. Mueller ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cd40 Ligand ◽  
Antioxidant Response ◽  
Immunoglobulin M ◽  
Inhibitory Protein ◽  
Wehi 231 ◽  
Immature Mouse

Signaling through the CD40 receptor on human and murine B lymphocytes is necessary for germinal center formation and immunoglobulin class switching in vivo and rescues B cells from apoptosis triggered by cross-linking of surface immunoglobulin M in vitro. Ligation of CD40 on the immature mouse B cell line WEHI-231 with recombinant CD40 ligand (CD40L) was found to protect cells from apoptosis after gamma irradiation, as well as that following treatment with the sphingomyelin ceramide or compounds that deplete intracellular glutathione. CD40 signaling led to a rapid increase in the expression of the apoptosis inhibitory protein Bcl-xL. In addition, the apoptosis-induced accumulation of intracellular oxidants in WEHI-231 B cells was rapidly diminished by CD40 crosslinking. This antioxidant response was observed within 1 h and coincided with a preservation of intracellular thiols. These findings indicate that CD40 signaling induces a generalized cellular resistance to apoptosis characterized by an upregulation of Bcl-xL and changes in the intracellular redox potential.

scholarly journals Antiplasmodial Activity of [(Aryl)arylsulfanylmethyl]Pyridine

2007 ◽  
Vol 52 (2) ◽  
pp. 705-715 ◽  
Author(s):  
Sanjay Kumar ◽  
Sajal Kumar Das ◽  
Sumanta Dey ◽  
Pallab Maity ◽  
Mithu Guha ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Malaria Parasite ◽  
Spin Trap ◽  
Antimalarial Activity ◽  
Lipid Peroxide ◽  
Food Vacuole ◽  
Mitochondrial Potential ◽  
Free Heme

ABSTRACT A series of [(aryl)arylsufanylmethyl]pyridines (AASMP) have been synthesized. These compounds inhibited hemozoin formation, formed complexes (KD = 12 to 20 μM) with free heme (ferriprotoporphyrin IX) at a pH close to the pH of the parasite food vacuole, and exhibited antimalarial activity in vitro. The inhibition of hemozoin formation may develop oxidative stress in Plasmodium falciparum due to the accumulation of free heme. Interestingly, AASMP developed oxidative stress in the parasite, as evident from the decreased level of glutathione and increased formation of lipid peroxide, H2O2, and hydroxyl radical (·OH) in P. falciparum. AASMP also caused mitochondrial dysfunction by decreasing mitochondrial potential (ΔΨm) in malaria parasite, as measured by both flow cytometry and fluorescence microscopy. Furthermore, the generation of ·OH may be mainly responsible for the antimalarial effect of AASMP since ·OH scavengers such as mannitol, as well as spin trap α-phenyl-n-tertbutylnitrone, significantly protected P. falciparum from AASMP-mediated growth inhibition. Cytotoxicity testing of the active compounds showed selective activity against malaria parasite with selectivity indices greater than 100. AASMP also exhibited profound antimalarial activity in vivo against chloroquine resistant P. yoelii. Thus, AASMP represents a novel class of antimalarial.

Modulation of cigarette smoke extract-induced human bronchial epithelial damage by eucalyptol and curcumin

2021 ◽  
pp. 096032712199798
Author(s):  
R Reis ◽  
D Orak ◽  
D Yilmaz ◽  
H Cimen ◽  
H Sipahi
Keyword(s):  
Inflammatory Response ◽  
Cigarette Smoke ◽  
Cell Injury ◽  
Nuclear Translocation ◽  
Regulatory Protein ◽  
Antioxidant Response ◽  
Protective Mechanism ◽  
Bronchial Epithelial

Smoking is one of the most important leading death cause worldwide. From a toxicological perspective, cigarette smoke serves hazards especially for the human being exposed to passive smoke. Over the last decades, the effects of natural compounds on smoking-mediated respiratory diseases such as COPD, asthma, and lung cancer have been under investigation, as well as the mechanistic aspects of disease progression. In the present study, the protective mechanism of eucalyptol (EUC), curcumin (CUR), and their combination on BEAS-2B cells were investigated in vitro to understand their impact on cell death, oxidative cell injury, and inflammatory response induced by 3R4F reference cigarette extract (CSE). According to the present findings, EUC, CUR, and their combination improved cell viability, attenuated CSE-induced apoptosis, and LC3B expression. Further, CSE-induced oxidative damage and inflammatory response in human bronchial epithelial cells were remarkably reduced by the combination treatment through modification of enzymatic antioxidant activity, GSH, MDA, and intracellular ROS levels as well as nitrite and IL-6 levels. In addition, nuclear translocation of Nrf2, a regulatory protein involved in the indirect antioxidant response, was remarkably up-regulated with the combination pre-treatment. In conclusion, EUC and CUR in combination might be a potential therapeutic against smoking-induced lung diseases through antioxidant and inflammatory pathways and results represent valuable background for future in vivo pulmonary toxicity studies.

Therapeutic Efficacy of Natural Compounds From Viscum Album l. In Acute Lymphoblastic Leukemia

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3261-3261
Author(s):  
Catharina I. Delebinski ◽  
Sebastian Jaeger ◽  
Kristin Kemnitz-Hassanin ◽  
Arend von Stackelberg ◽  
Günter Henze ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Scid Mouse ◽  
Lymphoblastic Leukemia ◽  
Viscum Album ◽  
Mitochondrial Potential ◽  
Scid Mouse Model ◽  
Mistletoe Extracts ◽  
First Time

Abstract Abstract 3261 Viscum album L. (mistletoe) is one of the most widely used complementary cancer therapies. Due to their low solubility, aqueous extracts contain hardly any triterpenes which are known to possess anti-tumoral properties. Using cyclodextrins it was possible to solubilisate mistletoe triterpenes (mainly oleanolic acid (OA)) and achieve a plant extract with high levels of OA and mistletoe lectins (ML). In the present study, we determined for the first time the effect of clearly defined mistletoe extracts against human acute lymphoblastic leukemia (ALL) in vitro and in vivo. These mistletoe extracts contain either lectins (aqueous extract, viscum) or cyclodextrin solubilised triterpenes (STE) such as oleanolic - and betulinic acid and combinations thereof (viscumTT). We used the C.B-17/SCID mouse model and tested efficacy and mechanisms of the treatment with these preparations in vitro and in vivo. The human leukemia cell line NALM-6 was incubated with increasing concentrations of mistletoe preparations (10-60 μg/ml OA; 0.8–8 ng/ml ML) and tested for their cytotoxicity in vitro. Apoptosis was determined using mitochondrial potential, DNA fragmentation and Annexin/PI assays. In vivo efficacy was determined in the C.B-17/SCID mouse model. For this purpose, 1×106 NALM-6 cells were injected IV into groups of C.B-17/SCID mice (n=8) and STE extracts were administered three times per week for 14 days by intraperitoneal (IP) injection. Viscum album L. extracts inhibited cell proliferation and show cytotoxic properties in vitro. The highest level of apoptosis with a decrease of the mitochondrial potential was observed with STE preparation at a concentration of 50 μg/ml OA and for lectin-treated cells for 4.7 ng/ml (IC50). To exclude an unwanted cell death via necrosis, LDH release was measured after 4h of incubation with different doses and extracts of Viscum album L without significant LDH release. Based on these data, we investigated the effect of Viscum album L. extracts in vivo. For this purpose 40 mg/kg/day oleanolic acid (STE), 3 μg/kg/day lectin (viscum) or a combination thereof (viscumTT) were administered IP. In line with the in vitro results, mice treated with viscumTT showed a significant longer survival. Mice receiving PBS had a mean survival time of 38 days whereas mice treated with viscumTT had a mean survival of 50,5 days (p=0,005). In summary, we demonstrate for the first time that either solubilised triterpenes or lectins and combinations thereof induce dose- and time-dependent apoptosis in the ALL cell line NALM-6. Based on the in vivo data we believe that triterpene containing Viscum album L. extracts may possess an impressive therapeutic potential. Thus, our investigations provide an important base line for the design of further experimental studies and clinical trials to investigate the effects of individual components and potential synergisms in ALL. Disclosures: No relevant conflicts of interest to declare.

Met-RANTES reduces endothelial progenitor cell homing to activated (glomerular) endothelium in vitro and in vivo

2007 ◽  
Vol 293 (2) ◽  
pp. F624-F630 ◽  
Author(s):  
Maarten B. Rookmaaker ◽  
Marianne C. Verhaar ◽  
Hetty C. de Boer ◽  
Roel Goldschmeding ◽  
Jaap A. Joles ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Vascular Repair ◽  
Endothelial Progenitor ◽  
Receptor Inhibition ◽  
Cd34 Cells ◽  
Glomerular Endothelium ◽  
Transplantation Model

The chemokine RANTES (regulated upon activation normal T-cell expressed and secreted) is involved in the formation of an inflammatory infiltrate during glomerulonephritis. However, RANTES receptor inhibition, although reducing glomerular leukocyte infiltration, can also increase damage. We hypothesized that RANTES does not only promote the influx and activation of inflammatory leukocytes but also mediates glomerular microvascular repair by stimulating the homing of bone marrow (BM)-derived endothelial progenitor cells. To investigate the role of RANTES in the participation of BM-derived cells in glomerular vascular repair, we used a rat BM transplantation model in combination with reversible anti-Thy-1.1 glomerulonephritis. Twenty-four hours after the induction of glomerulonephritis, BM-transplanted rats were treated for 7 days with either the RANTES receptor antagonist Met-RANTES or saline. The participation of BM-derived endothelial cells in glomerular repair, glomerular monocyte infiltration, and proteinuria was evaluated at days 7 and 28. Furthermore, we used an in vitro perfusion chamber assay to study the role of RANTES receptors in shear-resistant adhesion of the CD34+ stem cells to activated endothelium under flow. In our reversible glomerulonephritis model, RANTES receptor inhibition specifically reduced the participation of BM-derived cells in glomerular vascular repair by more than 40% at day 7 without impairing monocyte influx. However, no obvious change in recovery from proteinuria or morphological damage was observed. Blockade of RANTES receptors on CD34+ cells in vitro partially inhibited platelet-enhanced, shear-resistant firm adhesion of the CD34+ cells to activated endothelium. In conclusion, our data suggest that RANTES is involved in the homing and participation of BM-derived endothelial cells in glomerular repair.

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