Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
Add more filters










Database
Language
Publication year range
1.
Parasite Immunol ; 45(10): e13005, 2023 10.
Article in English | MEDLINE | ID: mdl-37467029

ABSTRACT

Chagas disease is a neglected tropical disease with only two drugs available for treatment and the plant Cecropia pachystachya has several compounds with antimicrobial and anti-inflammatory activities. This study aimed to evaluate a supercritical extract from C. pachystachya leaves in vitro and in vivo against Trypanosoma cruzi. A supercritical CO2 extraction was used to obtain the extract (CPE). Cytotoxicity and immunostimulation ability were evaluated in macrophages, and the in vitro trypanocidal activity was evaluated against epimastigotes and trypomastigotes forms. In vivo tests were done by infecting BALB/c mice with blood trypomastigotes forms and treating animals orally with CPE for 10 days. The parasitemia, survival rate, weight, cytokines and nitric oxide dosage were evaluated. CPE demonstrated an effect on the epi and trypomastigotes forms of the parasite (IC50 17.90 ± 1.2 µg/mL; LC50 26.73 ± 1.2 µg/mL) and no changes in macrophages viability, resulting in a selectivity index similar to the reference drug. CPE-treated animals had a worsening compared to non-treated, demonstrated by higher parasitemia and lower survival rate. This result was attributed to the anti-inflammatory effect of CPE, demonstrated by the higher IL-10 and IL-4 values observed in the treated mice compared to the control ones. CPE demonstrated a trypanocidal effect in vitro and a worsening in the in vivo infection due to its anti-inflammatory activity.


Subject(s)
Chagas Disease , Triterpenes , Trypanocidal Agents , Trypanosoma cruzi , Mice , Animals , Parasitemia/drug therapy , Trypanocidal Agents/pharmacology , Trypanocidal Agents/therapeutic use , Chagas Disease/drug therapy , Trypanosoma cruzi/physiology , Mice, Inbred BALB C , Triterpenes/pharmacology , Triterpenes/therapeutic use , Plant Extracts/pharmacology , Plant Extracts/therapeutic use , Ursolic Acid
2.
Diabetes ; 70(1): 111-118, 2021 01.
Article in English | MEDLINE | ID: mdl-32826297

ABSTRACT

Glucose-stimulated insulin secretion is the hallmark of the pancreatic ß-cell, a critical player in the regulation of blood glucose concentration. In 1974, the remarkable observation was made that an efflux of intracellular inorganic phosphate (Pi) accompanied the events of stimulated insulin secretion. The mechanism behind this "phosphate flush," its association with insulin secretion, and its regulation have since then remained a mystery. We recapitulated the phosphate flush in the MIN6m9 ß-cell line and pseudoislets. We demonstrated that knockdown of XPR1, a phosphate transporter present in MIN6m9 cells and pancreatic islets, prevented this flush. Concomitantly, XPR1 silencing led to intracellular Pi accumulation and a potential impact on Ca2+ signaling. XPR1 knockdown slightly blunted first-phase glucose-stimulated insulin secretion in MIN6m9 cells, but had no significant impact on pseudoislet secretion. In keeping with other cell types, basal Pi efflux was stimulated by inositol pyrophosphates, and basal intracellular Pi accumulated following knockdown of inositol hexakisphosphate kinases. However, the glucose-driven phosphate flush occurred despite inositol pyrophosphate depletion. Finally, while it is unlikely that XPR1 directly affects exocytosis, it may protect Ca2+ signaling. Thus, we have revealed XPR1 as the missing mediator of the phosphate flush, shedding light on a 45-year-old mystery.


Subject(s)
Insulin Secretion/genetics , Insulin-Secreting Cells/metabolism , Phosphates/metabolism , Receptors, G-Protein-Coupled/metabolism , Receptors, Virus/metabolism , Animals , Calcium/metabolism , Exocytosis/genetics , Gene Knockdown Techniques , Glucose/metabolism , Insulin/metabolism , Islets of Langerhans/metabolism , Male , Mice , Receptors, G-Protein-Coupled/genetics , Receptors, Virus/genetics , Signal Transduction/physiology , Xenotropic and Polytropic Retrovirus Receptor
3.
Cell Signal ; 42: 127-133, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29042286

ABSTRACT

Inositol pyrophosphates have emerged as important regulators of many critical cellular processes from vesicle trafficking and cytoskeletal rearrangement to telomere length regulation and apoptosis. We have previously demonstrated that 5-di-phosphoinositol pentakisphosphate, IP7, is at a high level in pancreatic ß-cells and is important for insulin exocytosis. To better understand IP7 regulation in ß-cells, we used an insulin secreting cell line, HIT-T15, to screen a number of different pharmacological inhibitors of inositide metabolism for their impact on cellular IP7. Although the inhibitors have diverse targets, they all perturbed IP7 levels. This made us suspicious that indirect, off-target effects of the inhibitors could be involved. It is known that IP7 levels are decreased by metabolic poisons. The fact that the inositol hexakisphosphate kinases (IP6Ks) have a high Km for ATP makes IP7 synthesis potentially vulnerable to ATP depletion. Furthermore, many kinase inhibitors are targeted to the ATP binding site of kinases, but given the similarity of such sites, high specificity is difficult to achieve. Here, we show that IP7 concentrations in HIT-T15 cells were reduced by inhibitors of PI3K (wortmannin, LY294002), PI4K (Phenylarsine Oxide, PAO), PLC (U73122) and the insulin receptor (HNMPA). Each of these inhibitors also decreased the ATP/ADP ratio. Thus reagents that compromise energy metabolism reduce IP7 indirectly. Additionally, PAO, U73122 and LY294002 also directly inhibited the activity of purified IP6K. These data are of particular concern for those studying signal transduction in pancreatic ß-cells, but also highlight the fact that employment of these inhibitors could have erroneously suggested the involvement of key signal transduction pathways in various cellular processes. Conversely, IP7's role in cellular signal transduction is likely to have been underestimated.


Subject(s)
Adenosine Triphosphate/metabolism , Enzyme Inhibitors/pharmacology , Inositol Phosphates/antagonists & inhibitors , Insulin-Secreting Cells/drug effects , Phosphotransferases (Phosphate Group Acceptor)/antagonists & inhibitors , Adenosine Diphosphate/metabolism , Adenosine Triphosphate/antagonists & inhibitors , Androstadienes/pharmacology , Animals , Arsenicals/pharmacology , Cell Line , Chromones/pharmacology , Cricetulus , Estrenes/pharmacology , Gene Expression , Humans , Inositol Phosphates/metabolism , Insulin/biosynthesis , Insulin/metabolism , Insulin Secretion , Insulin-Secreting Cells/cytology , Insulin-Secreting Cells/metabolism , Morpholines/pharmacology , Phosphotransferases (Phosphate Group Acceptor)/genetics , Phosphotransferases (Phosphate Group Acceptor)/metabolism , Pyrrolidinones/pharmacology , Receptor, Insulin/pharmacology , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Succinimides/pharmacology , Triazoles/pharmacology , Wortmannin
4.
Cell Physiol Biochem ; 42(5): 2093-2104, 2017.
Article in English | MEDLINE | ID: mdl-28810254

ABSTRACT

BACKGROUND/AIMS: Diabetic subjects are more susceptible to infections, which is partially due to insulin deficiency and hyperglycemia. We hypothesized that insulin influences cytokine release by macrophages from diabetic C57BL/6 mice stimulated with lipopolysaccharides (LPS). METHODS: Bone marrow-derived macrophages (BMDM) and tissue-specific macrophages from diabetic (alloxan 60 mg/kg, i.v.) male C57BL/6 mice were stimulated by LPS (100 ng/mL) and/or treated by insulin (1 mU/mL). RESULTS: Using BMDM from diabetic mice, we showed that LPS induced an increase in TNF-α and IL-6 release and p38, SAPK/JNK, ERK 1/2, and Akt (308-Thr and 473-Ser) phosphorylation but not in PKCα/ß II and delta. Insulin increased TNF-α and IL-6 secretion in LPS-stimulated macrophages as well as p-p38, p-SAPK/JNK, p-ERK 1/2, p-PI3K (p55) and p-Akt (473-Ser) expression. Furthermore, PI3-kinase inhibition by wortmannin decreased TNF-α release, and inhibition by LY294002 decreased both TNF-α and IL-6 levels after LPS-insulin treatment. PD98059, which inhibits the ERK upstream activators MAPK kinase (MKK) 1 and MKK2, reduced the effect promoted by insulin in BMDM stimulated by LPS In tissue-specific macrophages, insulin reduced LPS-induced TNF-α, IL-6 and IL-1ß secretion in alveolar and peritoneal macrophages. CONCLUSION: These data suggest that insulin through the modulation of PI3-kinase and ERK 1/2 pathways drive different responses in macrophages, thereby enhancing our understanding of the plasticity of these cells.


Subject(s)
Insulin/pharmacology , Interleukin-6/metabolism , Lipopolysaccharides/toxicity , Macrophages/drug effects , Tumor Necrosis Factor-alpha/metabolism , Androstadienes/pharmacology , Animals , Bone Marrow Cells/cytology , Cell Survival/drug effects , Cells, Cultured , Diabetes Mellitus, Experimental/chemically induced , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/pathology , Flavonoids/pharmacology , Macrophages/cytology , Macrophages/metabolism , Macrophages, Alveolar/cytology , Macrophages, Alveolar/drug effects , Macrophages, Alveolar/metabolism , Macrophages, Peritoneal/cytology , Macrophages, Peritoneal/drug effects , Macrophages, Peritoneal/metabolism , Male , Mice , Mice, Inbred C57BL , Mitogen-Activated Protein Kinase 1/antagonists & inhibitors , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/antagonists & inhibitors , Mitogen-Activated Protein Kinase 3/metabolism , Signal Transduction/drug effects , Wortmannin
5.
Biomed Res Int ; 2015: 568408, 2015.
Article in English | MEDLINE | ID: mdl-25866794

ABSTRACT

The biosynthesis pathway of eicosanoids derived from arachidonic acid, such as prostaglandins and leukotrienes, relates to the pathophysiology of diabetes mellitus (DM). A better understanding of how lipid mediators modulate the inflammatory process may help recognize key factors underlying the progression of diabetes complications. Our review presents recent knowledge about eicosanoid synthesis and signaling in DM-related complications, and discusses eicosanoid-related target therapeutics.


Subject(s)
Diabetes Mellitus/metabolism , Eicosanoic Acids/metabolism , Inflammation Mediators/metabolism , Signal Transduction , Animals , Humans
SELECTION OF CITATIONS
SEARCH DETAIL
...