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1.
Org Biomol Chem ; 22(26): 5333-5345, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38853721

RESUMO

The reactivity of 4-hydroxy-2H-chromene-2-thione is investigated with aryl aldehydes and 5,5-dimethylcylohexane-1,3-dione (dimedone) in the presence of 20 mol% L-proline in toluene at 90 °C. Instead of the expected linear product with a sulphur atom in the ring provided by 4-hydroxydithiocoumarin or an angular product obtained from 4-hydroxycoumarin, the hitherto unreported products, 12-aryl substituted chromeno[2,3-b]chromenes (4), were obtained in good to excellent yields. The reaction proceeds through a three-component reaction via Knoevenagel condensation between dimedone with an aromatic aldehyde followed by Michael addition with 4-hydroxy-2H-chromene-2-thione. In addition, a molecular docking study of all the derivatives was performed and among them, four compounds exhibited anti-proliferative activity and elevated ROS generation in breast cancer (MCF7) cell lines.

2.
Bioorg Chem ; 141: 106900, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37813073

RESUMO

The synthesis of hitherto unreported 3-sulfenylindole derivatives is achieved from 4-hydroxy-2H-chromene-2-thione (1) and indole (2) by employing an oxidative cross-dehydrogenative coupling reaction using a combination of 10 mol% of molecular iodine and 1 equivalent of TBHP in DMSO at room temperature. Then, the 3-sulfenylindole derivatives 3a, 3b, 3d, 3f, 3 h, and 3 k were converted into their corresponding sulfone derivatives because of lead likeness properties. Subsequently, a target prediction and docking study of six sulfone derivatives (5a-f) was performed, and four sulfones, namely 5a, 5d, 5e, and 5f, were selected for further in-vitro studies. The four sulfones mentioned above exhibited prominent anti-proliferative activity on breast cancer (MCF7) cell lines. In addition, this reaction was exergonic through quantum chemical analysis of the mechanistic steps. The salient features of this reaction are mild reaction conditions, good yields, and broad substrate scope.


Assuntos
Antineoplásicos , Indóis , Tionas , Humanos , Antineoplásicos/química , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Indóis/química , Estrutura Molecular , Estresse Oxidativo , Relação Estrutura-Atividade , Sulfonas/farmacologia , Tionas/química , Benzopiranos/química
3.
Methods Mol Biol ; 2455: 63-71, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35212986

RESUMO

Intestinal lipid absorption as well as secretion of absorbed lipids as chylomicrons by the enterocytes is a direct measure of the availability of dietary lipids. Measurement of this parameter is central to the understanding of the influence of diet on plasma lipids, specifically when modulation of intestinal lipid absorption by targeted interventions is being examined. In the post-prandial state, very low-density lipoprotein (VLDL) secreted from the liver represent the major source of plasma lipids and rate of VLDL secretion reports on hepatic lipid homeostasis. Here, we describe the methods to specifically measure secretion of chylomicron and VLDL in vivo. Tight regulation of dietary lipid absorption (chylomicron secretion) and hepatic secretion of VLDL underlies the development of dyslipidemia preceding hepatic lipid accumulation seen in non-alcoholic fatty liver disease (NAFLD) and subsequent progression to non-alcoholic steatohepatitis (NASH) underscoring the importance of measurement of lipoprotein secretion in vivo.


Assuntos
Quilomícrons , Lipoproteínas VLDL , Gorduras na Dieta , Lipoproteínas , Fígado , Triglicerídeos
4.
Nanomedicine (Lond) ; 16(21): 1843-1856, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34369819

RESUMO

Aim: The primary aim of this study was to develop biomimetic nanocarriers for specific homologous targeting of the anticancer drugs ammonium pyrrolidine dithiocarbamate (PDTC) and doxorubicin. Methods: Membranous nanovesicles were synthesized from a breast cancer cell line (MCF7) by syringe extrusion process and were loaded with PDTC and doxorubicin. Besides their abilities for self-homing, the drug-loaded nanovesicles showed anti-cell proliferative effects via the generation of reactive oxygen species. Results: The nanovesicles demonstrated efficient internalization via homologous targeting. Delivery of PDTC showed a higher killing effect for homologous cell targeting than other cell types. Experimental results demonstrated increased antiproliferative potency of PDTC, which induced apoptosis via reactive oxygen species generation. Conclusion: The developed membrane-derived nanocarrier is an attractive biocompatible system for ex vivo targeted drug delivery.


Assuntos
Antineoplásicos , Neoplasias , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Neoplasias/tratamento farmacológico , Espécies Reativas de Oxigênio
5.
Org Biomol Chem ; 19(26): 5818-5826, 2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34113949

RESUMO

The hitherto unreported 2-aryl-10H-thiochromeno[3,2-b][1,4]oxathiin-10-one derivatives are obtained in a single pot from 4-hydroxydithiocoumarins, arylacetylenes and dimethyl sulfoxide in the presence of 10 mol% CuI and K2CO3 in an oil bath at 70 °C. The novelties of the present protocol are (i) selective C-H functionalization at the C-3 position of 4-hydroxydithiocoumarin, (ii) regioselective hydrothiolation with arylacetylenes and (iii) concomitant cyclisation. The major advantages are mild reaction conditions, broad substrate scope and good yield. Among the synthesized compounds, the following five compounds 3aa, 3bd, 3ec, 3fa, and 3fd showed anticancer activity against a human breast cancer cell line (MCF-7) and a cervical cancer cell line (HeLa).

8.
Biochimie ; 176: 31-44, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32585227

RESUMO

Nerve growth factor (NGF) is a minor and neglected component of snake venom. Present study describes the purification and characterization of a NGF isoform (RVV-NGFa) from Indian Russell's viper venom (RVV). RVV-NGFa showed a protonated molecular ion [MH+] at m/z 17388.725 Da. The RVV-NGFa induced neuritogenesis in PC-12 cells but did not show cytotoxicity in mammalian cells, hemolytic activity, platelet modulation, and interference in blood coagulation system which are the characteristic pharmacological properties of RVV. By ELISA and immunofluorescence microplate reader assay, the RVV-NGFa showed appreciable binding to TrkA receptor expressed in breast cancer MDA-MB-231 and MCF-7 cells; nevertheless, pre-incubation of cells with anti-TrkA (and not TrkB or TrkC) or anti-p75NTR antibody significantly decreased (p < 0.05) this binding. The RVV-NGFa demonstrated insignificant binding with non-cancerous cells (HEK-293, L6) lacking TrkA receptor. The binding of RVV-NGFa to TrkA receptor of breast cancer cells resulted in internalization of ligand (RVV-NGFa)-receptor (TrkA) complex to cell cytoplasm in a time-dependent manner. The spectrofluorometric study demonstrated an interaction between RVV-NGFa and cytosolic domain of the purified TrkA receptor. The fluorescence (FITC)-tagged RVV-NGFa depicted a strong fluorescence signal that was observed under a fluorescence microscope and determined by fluorescence microplate reader assay post binding to breast cancer cells; but no fluorescence signal was detected after incubating FITC-RVV-NGFa with non-cancerous L6 and HEK-293 cells. The clinical application of FITC/fluorescence nanoparticle tagged RVV-NGFa for the ex vivo and in vivo diagnosis of breast cancer is highly promising.


Assuntos
Neoplasias da Mama , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Nanopartículas , Proteínas de Neoplasias/biossíntese , Fator de Crescimento Neural , Imagem Óptica , Receptor trkA/biossíntese , Venenos de Víboras , Animais , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/enzimologia , Feminino , Fluoresceína-5-Isotiocianato/química , Fluoresceína-5-Isotiocianato/farmacologia , Células HEK293 , Humanos , Células MCF-7 , Fator de Crescimento Neural/química , Fator de Crescimento Neural/farmacologia , Células PC12 , Ratos , Coloração e Rotulagem , Venenos de Víboras/química , Venenos de Víboras/farmacologia
9.
Org Biomol Chem ; 18(21): 4104-4113, 2020 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-32432294

RESUMO

An expedient and efficient synthetic method was developed for the oxidative cross dehydrogenative coupling reaction between 4-hydroxydithiocoumarin and indole at the C-3 position regio-selectively using a combination of 10 mol% molecular iodine and TBHP in the presence of 10 mol% CuBr2 as an additive at room temperature. Mild reaction conditions, good yields and a broad substrate scope are some of the salient features of the present protocol. Additionally, the synthesized 3-sulfenylindoles derived from 4-hydroxydithiocoumarin were converted into biologically active sulfone derivatives. Interestingly, some of the compounds exhibit anti-cell proliferative activity on breast cancer (MCF-7) cells due to reactive oxygen species (ROS) mediated cell damage.

10.
J Endocr Soc ; 4(2): bvz039, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32099951

RESUMO

The intestinal barrier is complex and consists of multiple layers, and it provides a physical and functional barrier to the transport of luminal contents to systemic circulation. While the epithelial cell layer and the outer/inner mucin layer constitute the physical barrier and are often referred to as the intestinal barrier, intestinal alkaline phosphatase (IAP) produced by epithelial cells and antibacterial proteins secreted by Panneth cells represent the functional barrier. While antibacterial proteins play an important role in the host defense against gut microbes, IAP detoxifies bacterial endotoxin lipopolysaccharide (LPS) by catalyzing the dephosphorylation of the active/toxic Lipid A moiety, preventing local inflammation as well as the translocation of active LPS into systemic circulation. The causal relationship between circulating LPS levels and the development of multiple diseases underscores the importance of detailed examination of changes in the "layers" of the intestinal barrier associated with disease development and how this dysfunction can be attenuated by targeted interventions. To develop targeted therapies for improving intestinal barrier function, it is imperative to have a deeper understanding of the intestinal barrier itself, the mechanisms underlying the development of diseases due to barrier dysfunction (eg, high circulating LPS levels), the assessment of intestinal barrier function under diseased conditions, and of how individual layers of the intestinal barrier can be beneficially modulated to potentially attenuate the development of associated diseases. This review summarizes the current knowledge of the composition of the intestinal barrier and its assessment and modulation for the development of potential therapies for barrier dysfunction-associated diseases.

11.
J Nutr ; 150(2): 285-293, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31586202

RESUMO

BACKGROUND: A Western-type diet (WD), rich in fat and cholesterol but deficient in fiber, induces development of diabetes and atherosclerosis. Colonic bacteria use the gut's mucous lining as an alternate energy source during periods of fiber deficiency, resulting in intestinal barrier erosion. OBJECTIVE: We hypothesized that supplementing a WD with galactooligosaccharide (GOS) fiber would attenuate WD-induced mucin layer disruption and attenuate development of metabolic diseases. METHODS: C57BL/6 mice (both sexes, 8-10 wk of age) were fed a standard rodent diet (TD7012, reference) or a high-fat, high-cholesterol-containing WD (TD88137, 21% fat, 0.15% cholesterol, 19.5% caesin) or a WD supplemented with 5% GOS fiber (TD170432, WD + GOS) for 16 wk. WD-fed mice that were gavaged daily with curcumin (100 mg/kg) served as positive controls. Glucose tolerance, colonic mucin layer, gene expression, and circulating macrophage/neutrophil levels were determined. Hyperlipidemic Ldlr-/- mice (both sexes, 8-10 wk of age) fed a WD with or without GOS supplementation (for 16 wk) were used to assess plasma LPS and atherosclerosis. Effects of dietary supplementation on different parameters were compared for each genotype. RESULTS: Compared with a WD, glucose tolerance was significantly improved in male C57BL/6 mice fed a WD + GOS (mean ± SEM: AUC = 53.6 ± 43.9 compared with 45.4 ± 33.3 g ⋅ min/dL; P = 0.015). Continuity of colonic mucin layer (MUC-2 expression) was improved in mice receiving GOS supplementation, indicating improved intestinal barrier. GOS supplementation also reduced circulating macrophages (30% decrease) and neutrophils (60% decrease), suggesting diminished systemic inflammation. In Ldlr-/- mice, GOS supplementation significantly reduced plasma LPS concentrations (mean ± SEM: 0.81 ±  0.43 EU/mL compared with 0.32 ± 0.26 EU/mL, P   < 0.0001, in females and 0.56 ± 0.24 EU/mL compared with 0.34 ± 0.12 EU/mL, P = 0.036, in males), improved glucose tolerance in male mice, and attenuated atherosclerotic lesion area (mean ± SEM: 54.2% ± 6.19% compared with 43.0% ± 35.12%, P   = 0.0006, in females and 54.6% ± 3.99% compared with 43.1% ± 8.11%, P = 0.003, in males). CONCLUSIONS: GOS fiber supplementation improves intestinal barrier in C57BL/6 and Ldlr-/- mice and significantly attenuates WD-induced metabolic diseases and, therefore, may represent a novel strategy for management of these diseases.


Assuntos
Aterosclerose/metabolismo , Colesterol na Dieta/administração & dosagem , Dieta Hiperlipídica , Suplementos Nutricionais , Galactose/química , Teste de Tolerância a Glucose , Mucosa Intestinal/metabolismo , Mucinas/metabolismo , Oligossacarídeos/administração & dosagem , Receptores de LDL/genética , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oligossacarídeos/química
12.
J Clin Med ; 8(8)2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31404980

RESUMO

Epithelial to mesenchymal transition (EMT) induces cell migration, invasion, and drug resistance, and consequently, contributes to cancer metastasis and disease aggressiveness. This study attempted to address crucial biological parameters to correlate EMT and drug-treated cancer cells traversing through microcapillaries, reminiscent of metastatic conditions. MDA-MB-468 breast cancer cells induced to undergo EMT by treatment with 20 ng/mL of epidermal growth factor (EGF) were initially passed through several blockages and then through a constricted microchannel, mimicking the flow of invasive metastatic cells through constricted blood microcapillaries. EMT cells acquired enhanced migratory properties and retained 50% viability, even after migration through wells 10-15 µm in size and a constricted passage of 7 µm and 150 µm in length at a constant flow rate of 50 µL/h. The hydrodynamic properties revealed cellular deformation with a deformation index, average transit velocity, and entry time of 2.45, 12.3 mm/s, and 31,000 µs, respectively for a cell of average diameter 19 µm passing through one of the 7 µm constricted sections. Interestingly, cells collected at the channel outlet regained epithelial character, undergoing reverse transition (mesenchymal to epithelial transition, MET) in the absence of EGF. Remarkably, real-time polymerase chain reaction (PCR) analysis confirmed increases of 2- and 2.7-fold in the vimentin and fibronectin expression in EMT cells, respectively; however, their expression reduced to basal level in the MET cells. A scratch assay revealed the pronounced migratory nature of EMT cells compared with MET cells. Furthermore, the number of colonies formed from EMT cells and paclitaxel-treated EMT cells after passing through a constriction were found to be 95 ± 10 and 79 ± 4, respectively, confirming that the EMT cells were more drug resistant with a concomitant two-fold higher expression of the multi-drug resistance (MDR1) gene. Our results highlight the hydrodynamic and drug-evading properties of cells that have undergone an EMT, when passed through a constricted microcapillary that mimics their journey in blood circulation.

13.
FEBS Lett ; 593(11): 1166-1178, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31026357

RESUMO

A causal relationship exists between macrophage cholesterol levels and inflammation, for example, Interleukin-1ß (IL-1ß) secretion. A decrease in intracellular K+ is essential for inflammasome activation/IL-1ß secretion and, herein, we examined the hypothesis that cellular cholesterol affects K+ -channel activity and K+ -efflux using mouse peritoneal macrophages (MPMs) and human/THP1 macrophages. An increase in cellular cholesterol led to a significant increase in K+ currents (> 350% in both MPM and THP1). Enhancing cholesterol efflux returned K+ currents back to basal levels with corresponding increase in intracellular K+ (11.2-14.5%) and reduced IL-1ß secretion (32-62%). These data demonstrate a novel mechanism by which cellular cholesterol modulates inflammation/inflammasome via regulation of K+ -channel activity and intracellular K+ levels. Attenuation of IL-1ß secretion by Nateglinide/Repaglinide further suggests involvement of Kir6 channels.


Assuntos
Exocitose , Interleucina-1beta/metabolismo , Macrófagos Peritoneais/metabolismo , Canais de Potássio/metabolismo , Animais , Células Cultivadas , Colesterol/metabolismo , Humanos , Inflamassomos/metabolismo , Camundongos , Potássio/metabolismo , Células THP-1
14.
Hepatol Commun ; 3(1): 63-73, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30619995

RESUMO

Patients with cirrhosis are growing older, which could have an impact on brain dysfunction beyond hepatic encephalopathy. Our aim was to study the effect of concomitant aging and cirrhosis on brain inflammation and degeneration using human and animal experiments. For the human study, age-matched patients with cirrhosis and controls between 65 and 85 years underwent cognitive testing, quality of life (QOL) assessment, and brain magnetic resonance (MR) spectroscopy and resting state functional MR imaging (rs-fMRI) analysis. Data were compared between groups. For the animal study, young (10-12 weeks) and old (1.5 years) C57BL/6 mice were given either CCl4 gavage to develop cirrhosis or a vehicle control and were followed for 12 weeks. Cortical messenger RNA (mRNA) expression of inflammatory mediators (interleukin [IL]-6, IL-1ß, transforming growth factor ß [TGF-ß], and monocyte chemoattractant protein 1), sirtuin-1, and gamma-aminobutyric acid (GABA)-ergic synaptic plasticity (neuroligin-2 [NLG2], discs large homolog 4 [DLG4], GABA receptor, subunit gamma 1/subunit B1 [GABRG1/B1]) were analyzed and compared between younger/older control and cirrhotic mice. The human study included 46 subjects (23/group). Patients with cirrhosis had worse QOL and cognition. On MR spectroscopy, patients with cirrhosis had worse changes related to ammonia and lower N-acetyl aspartate, whereas rs-fMRI analysis revealed that these patients demonstrated functional connectivity changes in the frontoparietal cortical region compared to controls. Results of the animal study showed that older mice required lower CCl4 to reach cirrhosis. Older mice, especially with cirrhosis, demonstrated higher cortical inflammatory mRNA expression of IL-6, IL-1ß, and TGF-ß; higher glial and microglial activation; and lower sirtuin-1 expression compared to younger mice. Older mice also had lower expression of DLG4, an excitatory synaptic organizer, and higher NLG2 and GABRG1/B1 receptor expression, indicating a predominantly inhibitory synaptic organization. Conclusion: Aging modulates brain changes in cirrhosis; this can affect QOL, cognition, and brain connectivity. Cortical inflammation, microglial activation, and altered GABA-ergic synaptic plasticity could be contributory.

15.
Nephrol Dial Transplant ; 34(5): 783-794, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30085297

RESUMO

BACKGROUND: The associated increase in the lipopolysaccharide (LPS) levels and uremic toxins in chronic kidney disease (CKD) has shifted the way we focus on intestinal microbiota. This study shows that a disruption of the intestinal barrier in CKD promotes leakage of LPS from the gut, subsequently decreasing insulin sensitivity. Butyrate treatment improved the intestinal barrier function by increasing colonic mucin and tight junction (TJ) proteins. This modulation further ameliorated metabolic functions such as insulin intolerance and improved renal function. METHODS: Renal failure was induced by 5/6th nephrectomy (Nx) in rats. A group of Nx and control rats received sodium butyrate in drinking water. The Nx groups were compared with sham-operated controls. RESULTS: The Nx rats had significant increases in serum creatinine, urea and proteinuria. These animals had impaired glucose and insulin tolerance and increased gluconeogenesis, which corresponded with decreased glucagon-like peptide-1 (GLP-1) secretion. The Nx animals suffered significant loss of intestinal TJ proteins, colonic mucin and mucin 2 protein. This was associated with a significant increase in circulating LPS, suggesting a leaky gut phenomenon. 5'adenosine monophosphate-activated protein kinase (AMPK) phosphorylation, known to modulate epithelial TJs and glucose metabolism, was significantly reduced in the intestine of the Nx group. Anti-inflammatory cytokine, interleukin 10, anti-bacterial peptide and cathelicidin-related antimicrobial peptide were also lowered in the Nx cohort. Butyrate treatment increased AMPK phosphorylation, improved renal function and controlled hyperglycemia. CONCLUSIONS: Butyrate improves AMPK phosphorylation, increases GLP-1 secretion and promotes colonic mucin and TJ proteins, which strengthen the gut wall. This decreases LPS leakage and inflammation. Taken together, butyrate improves metabolic parameters such as insulin resistance and markers of renal failure in CKD animals.


Assuntos
Ácido Butírico/farmacologia , Resistência à Insulina/fisiologia , Mucosa Intestinal/metabolismo , Mucinas/biossíntese , Insuficiência Renal Crônica/tratamento farmacológico , Animais , Modelos Animais de Doenças , Antagonistas dos Receptores Histamínicos/farmacologia , Imuno-Histoquímica , Masculino , Permeabilidade , Ratos , Insuficiência Renal Crônica/metabolismo
16.
Physiol Rep ; 6(14): e13790, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-30058275

RESUMO

Intestinal epithelial cell derived alkaline phosphatase (IAP) dephosphorylates/detoxifies bacterial endotoxin lipopolysaccharide (LPS) in the gut lumen. We have earlier demonstrated that consumption of high-fat high-cholesterol containing western type-diet (WD) significantly reduces IAP activity, increases intestinal permeability leading to increased plasma levels of LPS and glucose intolerance. Furthermore, oral supplementation with curcumin that increased IAP activity improved intestinal barrier function as well as glucose tolerance. To directly test the hypothesis that targeted increase in IAP would protect against WD-induced metabolic consequences, we developed intestine-specific IAP transgenic mice where expression of human chimeric IAP is under the control of intestine-specific villin promoter. This chimeric human IAP contains domains from human IAP and human placental alkaline phosphatase, has a higher turnover number, narrower substrate specificity, and selectivity for bacterial LPS. Chimeric IAP was specifically and uniformly overexpressed in these IAP transgenic (IAPTg) mice along the entire length of the intestine. While IAP activity reduced from proximal P1 segment to distal P9 segment in wild-type (WT) mice, this activity was maintained in the IAPTg mice. Dietary challenge with WD impaired glucose tolerance in WT mice and this intolerance was attenuated in IAPTg mice. Significant decrease in fecal zonulin, a marker for intestinal barrier dysfunction, in WD fed IAPTg mice and a corresponding decrease in translocation of orally administered nonabsorbable 4 kDa FITC dextran to plasma suggests that IAP overexpression improves intestinal barrier function. Thus, targeted increase in IAP activity represents a novel strategy to improve WD-induced intestinal barrier dysfunction and glucose intolerance.


Assuntos
Fosfatase Alcalina/metabolismo , Dieta Ocidental/efeitos adversos , Intolerância à Glucose/metabolismo , Mucosa Intestinal/metabolismo , Fosfatase Alcalina/genética , Animais , Células Cultivadas , Toxina da Cólera/metabolismo , Colesterol/efeitos adversos , Intolerância à Glucose/etiologia , Intolerância à Glucose/genética , Haptoglobinas , Humanos , Mucosa Intestinal/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Precursores de Proteínas
17.
Biotechnol Bioeng ; 115(5): 1116-1127, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29384195

RESUMO

Amalgamation of delivery and tracking of therapeutically relevant moieties on a single platform is made possible by the application of metal nanoclusters, an innovative class of luminescent nanomaterials. Metal nanoclusters, possessing molecule-like attributes, display extraordinary size and shape tunable properties befitting theranostic applications. Herein, we report successful assembly of therapeutically significant phosphatase protein PTEN and fluorescent lysozyme-stabilized silver nanoclusters to accomplish delivery and tracking of the protein. Down-regulation of PTEN perturbs the cellular networking leading to copious pathological conditions. The integration of purified recombinant PTEN with silver nanoclusters was evaluated by fluorescence spectroscopy study. A key feature of this study is the use of polyethylene glycol coating that allows fabrication of the assembly into spherical nanocomposites as characterized by transmission electron microscope along with retention of both optical functionality of the cluster and biological activity of the protein. Prior to cellular application, the functional integrity of PTEN in the composite was determined in vitro, by enzymatic assay employing para-nitrophenylphosphate as substrate. Cellular internalization of the cargo was studied by confocal microscopy and flow cytometry analysis. The efficacy of the payload on modulation of cellular signaling was assessed on cell lines that expressed PTEN differentially. PTEN null U-87 MG and PTEN expressing MCF7 cell lines displayed successful alteration of AKT and FAK signaling proteins culminating in cell cycle arrest and reduced wound healing capacity. A dose dependent reduction in cell proliferation of MCF7 cells was achieved. For U-87 MG, treatment with the payload resulted in chemosensitization toward anti-cancer drug erlotinib. Thus, PEG coated GST-PTEN loaded silver nanoclusters serves as a comprehensive system encompassing cellular imaging and protein delivery with potential biomedical implications.


Assuntos
Muramidase/metabolismo , Neoplasias/diagnóstico por imagem , Neoplasias/diagnóstico , PTEN Fosfo-Hidrolase/metabolismo , Prata/metabolismo , Nanomedicina Teranóstica/métodos , Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Transmissão de Doença Infecciosa , Cloridrato de Erlotinib/farmacologia , Citometria de Fluxo , Humanos , Células MCF-7 , Microscopia Confocal , Modelos Biológicos , Espectrometria de Fluorescência
18.
Tissue Barriers ; 6(1): e1425085, 2018 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-29420166

RESUMO

Curcumin has anti-inflammatory, anti-oxidant and anti-proliferative properties established largely by in vitro studies. Accordingly, oral administration of curcumin beneficially modulates many diseases including diabetes, fatty-liver disease, atherosclerosis, arthritis, cancer and neurological disorders such as depression, Alzheimer's or Parkinson's disease. However, limited bioavailability and inability to detect curcumin in circulation or target tissues has hindered the validation of a causal role. We established curcumin-mediated decrease in the release of gut bacteria-derived lipopolysaccharide (LPS) into circulation by maintaining the integrity of the intestinal barrier function as the mechanism underlying the attenuation of metabolic diseases (diabetes, atherosclerosis, kidney disease) by curcumin supplementation precluding the need for curcumin absorption. In view of the causative role of circulating LPS and resulting chronic inflammation in the development of diseases listed above, this review summarizes the mechanism by which curcumin affects the several layers of the intestinal barrier and, despite negligible absorption, can beneficially modulate these diseases.


Assuntos
Curcumina/uso terapêutico , Intestinos/efeitos dos fármacos , Curcumina/farmacologia , Humanos , Mucosa Intestinal/metabolismo
19.
Int J Biol Macromol ; 102: 1138-1145, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28476594

RESUMO

Granulocyte macrophage colony stimulating factor (GMCSF), a therapeutically important cytokine that helps in the proliferation of macrophages, was recombinantly expressed in E. coli BL21 and purified as a GST-tagged protein. Cell viability assay demonstrated significant enhancement in proliferation of RAW 264.7 (murine macrophage) in presence of GMCSF. In vitro activation of macrophages was carried out by lipopolysaccharide (LPS) or pyrogallol and probed by the generation of reactive oxygen species (ROS). Following the induction of apoptosis in A549 lung cancer cells with anticancer drug cisplatin (at 25µM), apoptotic cancer cells were effectively phagocytosed by the recombinant GMCSF-treated and exogenously activated RAW 264.7 cells as observed in fluorescence microscopic images. The current findings attribute possible role of GMCSF as adjuvant in scavenging treated cancer cells.


Assuntos
Apoptose , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Fagocitose/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Ativação de Macrófagos/efeitos dos fármacos , Camundongos , Células RAW 264.7
20.
Am J Physiol Cell Physiol ; 312(4): C438-C445, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28249988

RESUMO

Association between circulating lipopolysaccharide (LPS) and metabolic diseases (such as type 2 diabetes and atherosclerosis) has shifted the focus from high-fat high-cholesterol containing Western-type diet (WD)-induced changes in gut microbiota per se to release of gut bacteria-derived products (e.g., LPS) into circulation due to intestinal barrier dysfunction as the possible mechanism for the chronic inflammatory state underlying the development of these diseases. We demonstrated earlier that oral supplementation with curcumin attenuates WD-induced development of type 2 diabetes and atherosclerosis. Poor bioavailability of curcumin has precluded the establishment of a causal relationship between oral supplementation and it is in vivo effects. We hypothesized that curcumin attenuates WD-induced chronic inflammation and associated metabolic diseases by modulating the function of intestinal epithelial cells (IECs) and the intestinal barrier function. The objective of the present study was to delineate the underlying mechanisms. The human IEC lines Caco-2 and HT-29 were used for these studies and modulation of direct as well as indirect effects of LPS on intracellular signaling as well as tight junctions were examined. Pretreatment with curcumin significantly attenuated LPS-induced secretion of master cytokine IL-1ß from IECs and macrophages. Furthermore, curcumin also reduced IL-1ß-induced activation of p38 MAPK in IECs and subsequent increase in expression of myosin light chain kinase involved in the phosphorylation of tight junction proteins and ensuing disruption of their normal arrangement. The major site of action of curcumin is, therefore, likely the IECs and the intestinal barrier, and by reducing intestinal barrier dysfunction, curcumin modulates chronic inflammatory diseases despite poor bioavailability.


Assuntos
Comunicação Celular/imunologia , Colite/imunologia , Curcumina/administração & dosagem , Absorção Intestinal/imunologia , Mucosa Intestinal/imunologia , Junções Íntimas/imunologia , Células CACO-2 , Comunicação Celular/efeitos dos fármacos , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colo/efeitos dos fármacos , Colo/imunologia , Relação Dose-Resposta a Droga , Células Epiteliais , Células HT29 , Humanos , Absorção Intestinal/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Lipopolissacarídeos , Junções Íntimas/efeitos dos fármacos
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