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1.
Artigo em Inglês | MEDLINE | ID: mdl-38432617

RESUMO

BACKGROUND AND OBJECTIVES: The surgery of osseointegrated implants has undergone different modifications over the years with the aim of achieving better results and facilitating the surgical technique. Today the most commonly used technique is the linear incision with tissue preservation and placement of the abutment and implant. The long-term success of this technique has served as the basis for the development of the so-called minimally invasive surgical approach (MIPS). This study compares the short-, medium- and long-term results between the classic linear incision technique and the MIPS technique. MATERIAL AND METHODS: A prospective study was conducted on patients who had an osseointegrated implant placed between February 2016 and February 2020. A total of 59 surgeries were performed, 32 surgeries according to the linear incision technique with tissue preservation and 27 with MIPS technique. Outcomes were evaluated at one week, one month and one year. RESULTS: Statistically significant differences were achieved between the 2 groups at one week after surgery. Eighty per cent of the MIPS patients had Holgers grades 0-1 compared to 35% of the linear technique patients (p = 0.001). No statistically significant differences were observed at one month (p = 0.457) and one year (p = 0.228). One case with grade 4 was recorded which resulted in implant extrusion one month after surgery with the MIPS technique. A new osseointegrated implant was placed 2 months after the fall using the same MIPS technique with good results. We were also able to verify that the duration of surgery was much shorter with the MIPS technique and better tolerated in terms of postoperative discomfort by the patient. CONCLUSIONS: In our experience, the MIPS technique is the technique of choice for surgery of osseointegrated Ponto model implants as it is simpler, faster and presents fewer problems in the immediate postoperative period, with similar long-term postoperative results.

2.
Anal Chem ; 96(2): 615-619, 2024 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-38165272

RESUMO

STD NMR spectroscopy is a powerful ligand-observed NMR tool for screening and characterizing the interactions of small molecules and low molecular weight fragments with a given macromolecule, identifying the main intermolecular contacts in the bound state. It is also a powerful analytical technique for the accurate determination of protein-ligand dissociation constants (KD) of medium-to-weak affinity, of interest in the pharmaceutical industry. However, accurate KD determination and epitope mapping requires a long series of experiments at increasing saturation times to carry out a full analysis using the so-called STD NMR build-up curve approach and apply the "initial slopes approximation". Here, we have developed a new protocol to bypass this important limitation, which allows us to obtain initial slopes by using just two saturation times and, hence, to very quickly determine precise protein-ligand dissociation constants by STD NMR.


Assuntos
Imageamento por Ressonância Magnética , Proteínas , Ligantes , Proteínas/química , Espectroscopia de Ressonância Magnética/métodos , Mapeamento de Epitopos , Ligação Proteica
3.
Med. oral patol. oral cir. bucal (Internet) ; 29(1): e58-e66, Ene. 2024. tab
Artigo em Inglês | IBECS | ID: ibc-229189

RESUMO

Background: The number of patients treated with coagulation disorders, and more specifically with anticoagulanttherapy, has increased worldwide in recent years due to increased life expectancy in developed countries. Theprotocols for managing this type of patient in oral surgery has varied over recent years, especially after the appear-ance of new direct-acting oral anticoagulants (DOACs). The assessment of risk of bleeding in this type of patientwhen undergoing a surgical procedure continues to be a controversial issue for patients, dentists and general prac-titioners. The objective of this document is to offer recommendations, based on evidence, for decision making forpatients with coagulopathies who require dental surgical intervention. Material and Methods: Based on the indications of the “Preparation of Clinical Practice guidelines in the NationalHealth System. Methodological manual”, we gathered a group of experts who agreed on 15 PICO questions basedon managing patients with coagulation disorders in dental surgical procedures, such as fitting of implants or dentalextractions.Results: The 15 PICO questions were answered based on the available evidence, being limited in most cases due tothe lack of a control group. Two of the PICO questions were answered by the experts with a grade C recommendation,while the rest were answered with grade D.Conclusions: The results of this review highlight the need to undertake well designed clinical trials with controlgroups and with a representative sample size.(AU)


Assuntos
Humanos , Masculino , Feminino , Acenocumarol , Varfarina , Heparina , Implantes Dentários , Extração Dentária , Cirurgia Bucal , Inibidores do Fator Xa , Espanha , Odontologia , Medicina Bucal , Higiene Bucal , Transtornos da Coagulação Sanguínea
4.
J Periodontal Res ; 2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38140743

RESUMO

OBJECTIVE: The aim of this study was to analyze the effects of periodontal treatment on markers of atherosclerotic coronary artery disease and circulating levels of periostin. BACKGROUND: Periostin is necessary for periodontal stability, but it is highly present in atherosclerotic plaques. Treatment of periodontal disease, with low levels of local periostin, is thought to reduce systemic levels of periostin. Thus, this may contribute to cardiovascular health. METHODS: A pilot randomized controlled clinical trial was designed to include patients with severe periodontal disease and history of atherosclerotic coronary artery disease. Samples of gingival crevicular fluid (GCF) and serum were collected before and after periodontal treatment by periodontal surgery or non-surgical therapy. The levels of several markers of inflammation and cardiovascular damage were evaluated including CRP, IFN-γ, IL-1ß, IL-10, MIP-1α, periostin, and TNF-α in GCF and CRP, Fibrinogen, IFN-γ, IL-1ß, IL-6, IL-10, L-Selectin, MIP-1α, Periostin, TNF-α, and vWF in serum. RESULTS: A total of 22 patients with an average of 56 years old were recruited for participating in this study. Twenty of them were male. Most of them (82%) had suffered an acute myocardial event and underwent surgery for placing 1, 2, or 3 stents in the coronary arteries more than 6 months ago but less than 1 year. The treatment of periodontal disease resulted in an overall improvement of all periodontal parameters. Regarding the evaluation of GCF and serum, a significant increase of periostin in the GCF was observed after periodontal surgery. In contrast, although other markers in GCF and serum improved, no significant correlations were found. CONCLUSION: Treatment of periodontal disease through periodontal surgery induces a local and transient increase in the levels of periostin in the gingival crevicular fluid. The effects on systemic markers of inflammation and cardiovascular function have not been confirmed.

5.
Nanoscale Horiz ; 8(12): 1700-1710, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37819240

RESUMO

A selenium-containing metal-organic framework with remarkable antioxidant capacity and ROS-scavenging activity was constructed by a controlled de novo encapsulation approach of a glycoconjugate mimetic, specifically a sp2-iminoglycolipid bearing a selenoureido fragment (DSeU), within a zeolitic-imidazolate framework exoskeleton. Biocompatible and homogeneous nanosized particles of ∼70 nm (DSeU@ZIF8) were obtained, which could be efficiently internalized in cells, overcoming the poor solubility in biological media and limited bioavailability of glycolipids. The ZIF-particle served as nanocarrier for the intracellular delivery of the selenocompound to cells, promoted by the acidic pH inside endosomes/lysosomes. As demonstrated by in vitro studies, the designed DSeU@ZIF8 nanoparticles displayed a high antioxidant activity at low doses; lower intracellular ROS levels were observed upon the uptake of DSeU@ZIF8 by human endothelial cells. Even more interesting was the finding that these DSeU@ZIF8 particles were able to reverse to a certain level the oxidative stress induced in cells by pre-treatment with an oxidizing agent. This possibility of modulating the oxidative stress in living cells may have important implications in the treatment of diverse pathological complications that are generally accompanied with elevated ROS levels.


Assuntos
Antioxidantes , Nanopartículas , Humanos , Antioxidantes/uso terapêutico , Células Endoteliais , Espécies Reativas de Oxigênio , Estresse Oxidativo
6.
Eur J Med Chem ; 255: 115390, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37137247

RESUMO

The unique electronic properties of the fluorine atom make its strategic incorporation into a bioactive compound a very useful tool in the design of drugs with optimized pharmacological properties. In the field of the carbohydrates, its selective installation at C2 position has proven particularly interesting, some 2-deoxy-2-fluorosugar derivatives being currently in the market. We have now transferred this feature into immunoregulatory glycolipid mimetics that contain a sp2-iminosugar moiety, namely sp2-iminoglycolipids (sp2-IGLs). The synthesis of two epimeric series of 2-deoxy-2-fluoro-sp2-IGLs, structurally related to nojirimycin and mannonojirimycin, has been accomplished by sequential Selectfluor-mediated fluorination and thioglycosidation of sp2-iminoglycals. Exclusively the α-anomer is obtained regardless of the configurational profile of the sp2-IGL (d-gluco or d-manno), highlighting the overwhelming anomeric effect in these prototypes. Notably, the combination of a fluorine atom at C2 and an α-oriented sulfonyl dodecyl lipid moiety in compound 11 led to remarkable anti-proliferative properties, featuring similar GI50 values than the chemotherapy drug Cisplatin against several tumor cell lines and better selectivity. The biochemical data further evidence a strong reduction of the number of tumor cell colonies and apoptosis induction. Mechanistic investigations revealed that this fluoro-sp2-IGL induces the non-canonical activation mode of the mitogen-activated protein kinase signaling pathway, causing p38α autoactivation under an inflammatory context.


Assuntos
Carboidratos , Flúor , Flúor/química , Carboidratos/química , Glicolipídeos/química , Linhagem Celular Tumoral
7.
Chem Commun (Camb) ; 58(86): 12086-12089, 2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36219150

RESUMO

Selective DC-SIGN targeting vs. langerin might lead to anti-infective agents, given their counteracting effects upon infection by some pathogens. Here we show that multivalent sp2-iminosugar-containing mannobioside analogs can achieve total DC-SIGN selectivity by levering the canonic binding mode towards high-mannose oligosaccharide ligands, behaving as factual biomimics.


Assuntos
Biomimética , Lectinas de Ligação a Manose , Lectinas de Ligação a Manose/metabolismo , Antígenos CD/metabolismo , Sítios de Ligação , Lectinas Tipo C/metabolismo , Ligação Proteica
8.
Int J Mol Sci ; 23(15)2022 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-35955585

RESUMO

Inflammatory processes play a central role in the pathogenesis of diabetic nephropathy (DN) in the early stages of the disease. The authors demonstrate that the glycolipid mimetic (Ss)-DS-ONJ is able to abolish inflammation via the induction of autophagy flux and provokes the inhibition of inflammasome complex in ex vivo and in vitro models, using adult kidney explants from BB rats. The contribution of (Ss)-DS-ONJ to reducing inflammatory events is mediated by the inhibition of classical stress kinase pathways and the blocking of inflammasome complex activation. The (Ss)-DS-ONJ treatment is able to inhibit the epithelial-to-mesenchymal transition (EMT) progression, but only when the IL18 levels are reduced by the treatment. These findings suggest that (Ss)-DS-ONJ could be a novel, and multifactorial treatment for DN.


Assuntos
Diabetes Mellitus , Nefropatias Diabéticas , Animais , Autofagia , Nefropatias Diabéticas/metabolismo , Transição Epitelial-Mesenquimal , Inflamassomos , Rim/metabolismo , Ratos
9.
Molecules ; 26(24)2021 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-34946583

RESUMO

sp2-Iminosugar glycolipids (sp2-IGLs) represent a consolidated family of glycoconjugate mimetics encompassing a monosaccharide-like glycone moiety with a pseudoamide-type nitrogen replacing the endocyclic oxygen atom of carbohydrates and an axially-oriented lipid chain anchored at the pseudoanomeric position. The combination of these structural features makes them promising candidates for the treatment of a variety of conditions, spanning from cancer and inflammatory disorders to parasite infections. The exacerbated anomeric effect associated to the putative sp2-hybridized N-atom imparts chemical and enzymatic stability to sp2-IGLs and warrants total α-anomeric stereoselectivity in the key glycoconjugation step. A variety of O-, N-, C- and S-pseudoglycosides, differing in glycone configurational patterns and lipid nature, have been previously prepared and evaluated. Here we expand the chemical space of sp2-IGLs by reporting the synthesis of α-d-gluco-configured analogs with a bicyclic (5N,6O-oxomethylidene)nojirimycin (ONJ) core incorporating selenium at the glycosidic position. Structure-activity relationship studies in three different scenarios, namely cancer, Leishmaniasis and inflammation, convey that the therapeutic potential of the sp2-IGLs is highly dependent, not only on the length of the lipid chain (linear aliphatic C12 vs. C8), but also on the nature of the glycosidic atom (nitrogen vs. sulfur vs. selenium). The ensemble of results highlights the α-dodecylseleno-ONJ-glycoside as a promising multitarget drug candidate.


Assuntos
Anti-Inflamatórios/uso terapêutico , Antineoplásicos/uso terapêutico , Antiprotozoários/uso terapêutico , Glicolipídeos/uso terapêutico , Neoplasias/tratamento farmacológico , Compostos Organosselênicos/uso terapêutico , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/química , Antineoplásicos/síntese química , Antineoplásicos/química , Antiprotozoários/síntese química , Antiprotozoários/química , Glicolipídeos/síntese química , Glicolipídeos/química , Humanos , Inflamação/tratamento farmacológico , Leishmaniose/tratamento farmacológico , Compostos Organosselênicos/síntese química , Compostos Organosselênicos/química
10.
J Clin Med ; 10(22)2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34830709

RESUMO

The aim of this study was to analyze the differences in terms of the marginal bone level (MBL) around implants with either an internal conical or an internal hexagonal implant-prosthesis connection. A randomized clinical trial included patients in need of a single implant-supported restoration. The implant-prosthesis connection was either internal conical or internal hexagonal while maintaining the same type of implant macro- and microarchitecture. Clinical and radiographical variables were registered up to 12 months of follow-up, including MBL. A total of 30 patients were included in the study. The main outcome variable, MBL 12 months after prosthesis delivery, was statistically different in both groups: -0.25 (0.12) vs. -0.70 (0.43) (conical vs. hexagonal; p = 0.033). Differences were also observed at the 3- and 6-month follow-up visits as well as for the MBL change from prosthesis delivery to the 12-month follow-up (-0.15 (0.13) vs. -0.56 (0.44); conical vs. hexagonal; p = 0.023). Correlations between MBL around the implants and radiographic measurements on the adjacent teeth, buccal bone to implant, tissue thickness or keratinized tissue were not significant neither globally nor when analyzed independently by group. In view of such results, it can be concluded that single-unit restorations with internal hexagonal-connection implants induce higher marginal bone loss after 12 months of follow-up from prosthesis delivery than internal conical-connection implants.

11.
Front Immunol ; 12: 632132, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33815384

RESUMO

Diabetic retinopathy (DR) is one of the most common complications of Diabetes Mellitus (DM) and is directly associated with inflammatory processes. Currently, neuro-inflammation is considered an early event in DR and proceeds via microglia polarization. A hallmark of DR is the presence of retinal reactive gliosis. Here we report the beneficial effect of (SS,1R)-1-docecylsulfiny-5N,6O-oxomethylidenenojirimycin ((Ss)-DS-ONJ), a member of the sp2-iminosugar glycolipid (sp2-IGL) family, by decreasing iNOS and inflammasome activation in Bv.2 microglial cells exposed to pro-inflammatory stimuli. Moreover, pretreatment with (Ss)-DS-ONJ increased Heme-oxygenase (HO)-1 as well as interleukin 10 (IL10) expression in LPS-stimulated microglial cells, thereby promoting M2 (anti-inflammatory) response by the induction of Arginase-1. The results strongly suggest that this is the likely molecular mechanism involved in the anti-inflammatory effects of (SS)-DS-ONJ in microglia. (SS)-DS-ONJ further reduced gliosis in retinal explants from type 1 diabetic BB rats, which is consistent with the enhanced M2 response. In conclusion, targeting microglia polarization dynamics in M2 status by compounds with anti-inflammatory activities offers promising therapeutic interventions at early stages of DR.


Assuntos
Anti-Inflamatórios/uso terapêutico , Retinopatia Diabética/tratamento farmacológico , Glicolipídeos/uso terapêutico , Sulfóxidos/uso terapêutico , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Citocinas/metabolismo , Retinopatia Diabética/imunologia , Retinopatia Diabética/patologia , Gliose , Glicolipídeos/química , Glicolipídeos/farmacologia , Inflamassomos/efeitos dos fármacos , Inflamação , Lipopolissacarídeos/efeitos adversos , Microglia/efeitos dos fármacos , Microglia/imunologia , Óxido Nítrico Sintase Tipo II/metabolismo , Ratos , Retina/efeitos dos fármacos , Retina/imunologia , Retina/patologia , Transdução de Sinais/efeitos dos fármacos , Sulfóxidos/química , Sulfóxidos/farmacologia
12.
J Periodontal Implant Sci ; 51(1): 63-74, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33634616

RESUMO

PURPOSE: This study investigated the effects of hyaluronic acid (HA) on peri-implant clinical variables and crevicular concentrations of the proinflammatory biomarkers interleukin (IL)-1ß and tumor necrosis factor (TNF)-α in patients with peri-implantitis. METHODS: A randomized controlled trial was conducted in peri-implantitis patients. Patients were randomized to receive a 0.8% HA gel (test group), an excipient-based gel (control group 1), or no gel (control group 2). Clinical periodontal variables and marginal bone loss after 0, 45, and 90 days of treatment were assessed. IL-1ß and TNF-α levels in crevicular fluid were measured by enzyme-linked immunosorbent assays at baseline and after 45 days of treatment. Clustering analysis was performed, considering the possibility of multiple implants in a single patient. RESULTS: Sixty-one patients with 100 dental implants were assigned to the test group, control group 1, or control group 2. Probing pocket depth (PPD) was significantly lower in the test group than in both control groups at 45 days (control 1: 95% CI, -1.66, -0.40 mm; control 2: 95% CI, -1.07, -0.01 mm) and 90 days (control 1: 95% CI, -1.72, -0.54 mm; control 2: 95% CI, -1.13, -0.15 mm). There was a trend towards less bleeding on probing in the test group than in control group 2 at 90 days (P=0.07). Implants with a PPD ≥5 mm showed higher levels of IL-1ß in the control group 2 at 45 days than in the test group (P=0.04). CONCLUSIONS: This study demonstrates for the first time that the topical application of a HA gel in the peri-implant pocket and around implants with peri-implantitis may reduce inflammation and crevicular fluid IL-1ß levels. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03157193.

14.
J Med Chem ; 63(15): 8524-8533, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32672464

RESUMO

In many human carcinomas, mucin-1 (MUC1) is overexpressed and aberrantly glycosylated, resulting in the exposure of previously hidden antigens. This generates new patient antibody profiles that can be used in cancer diagnosis. In the present study, we focused on the MUC1-associated Tn antigen (α-O-GalNAc-Ser/Thr) and substituted the GalNAc monosaccharide by a glycomimic to identify MUC1-based glycopeptides with increased antigenicity. Two different glycopeptide libraries presenting the natural Tn antigen or the sp2-iminosugar analogue were synthesized and evaluated with anti-MUC1 monoclonal antibodies in a microarray platform. The most promising candidates were tested with healthy and breast cancer sera aiming for potential autoantibody-based biomarkers. The suitability of sp2-iminosugar glycopeptides to detect anti-MUC1 antibodies was demonstrated, and serological experiments showed stage I breast cancer autoantibodies binding with a specific unnatural glycopeptide with almost no healthy serum interaction. These results will promote further studies on their capabilities as early cancer biomarkers.


Assuntos
Antígenos Glicosídicos Associados a Tumores/imunologia , Autoanticorpos/imunologia , Neoplasias da Mama/imunologia , Mucina-1/imunologia , Antígenos Glicosídicos Associados a Tumores/química , Autoanticorpos/sangue , Neoplasias da Mama/sangue , Feminino , Glicômica , Humanos , Mucina-1/química , Biblioteca de Peptídeos
15.
J Org Chem ; 85(7): 5038-5047, 2020 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-32159355

RESUMO

The first examples of iminosugar-type 2-deoxy(thio)glycoside mimetics are reported. The key step is the activation of a bicyclic iminoglycal carbamate to generate a highly reactive acyliminium cation. Cerium(IV) ammonium nitrate efficiently promoted the formation of 2-deoxy S-glycosides in the presence of thiols, probably by in situ generation of catalytic HNO3, with complete α-stereoselectivity. Cooperative phosphoric acid/Schreiner's thiourea organocatalysis proved better suited for generating 2-deoxy O-glycosides, significantly broadening the scope of the approach.

16.
J Periodontol ; 91(6): 734-745, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31577041

RESUMO

BACKGROUND: The aim of our study was to evaluate the effects of a hyaluronic acid (HA) gel at 45 days on the microbiome of implants with peri-implantitis with at least 1 year of loading. METHODS: A randomized controlled trial was conducted in peri-implantitis patients. Swabs containing the samples were collected both at baseline and after 45 days of treatment. 16S rRNA sequencing techniques were used to investigate the effect of HA gel on the subgingival microbiome. RESULTS: One hundred and eight samples of 54 patients were analyzed at baseline and after follow-up at 45 days. Three strata with different microbial composition were obtained in the samples at baseline, representing three main microbial consortia associated with peri-implantitis. Stratum 1 did not show any difference for any variable after treatment with HA, whereas in stratum 2, Streptococcus, Veillonella, Rothia, and Granulicatella did decrease (P < 0.05). Similarly, Prevotella and Campylobacter (P < 0.05) decreased in stratum 3 after treatment with HA. Microbial diversity was found to be decreased in stratum 3 (P < 0.05) after treatment with HA compared with the control group, in which an increase was found (P < 0.05). CONCLUSIONS: HA reduced the relative abundance of peri-implantitis-related microorganisms, especially the early colonizing bacteria, suggesting a specific action during the first stages in the development of the disease. HA did not alter relative abundances of non-oral genera. The use of HA in advanced stages of peri-implantitis resulted in a decrease in microbial alpha diversity, suggesting a protective action of the peri-implant site against bacteria colonization.


Assuntos
Implantes Dentários , Microbiota , Peri-Implantite , Bactérias/genética , Humanos , Ácido Hialurônico , Peri-Implantite/tratamento farmacológico , RNA Ribossômico 16S/genética
17.
Chem Sci ; 11(15): 3996-4006, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-34122869

RESUMO

The Tn antigen (GalNAc-α-1-O-Thr/Ser) is a well-known tumor-associated carbohydrate determinant. The use of glycopeptides that incorporate this structure has become a significant and promising niche of research owing to their potential use as anticancer vaccines. Herein, the conformational preferences of a glycopeptide with an unnatural Tn antigen, characterized by a threonine decorated with an sp2-iminosugar-type α-GalNAc mimic, have been studied both in solution, by combining NMR spectroscopy and molecular dynamics simulations, and in the solid state bound to an anti-mucin-1 (MUC1) antibody, by X-ray crystallography. The Tn surrogate can mimic the main conformer sampled by the natural antigen in solution and exhibits high affinity towards anti-MUC1 antibodies. Encouraged by these data, a cancer vaccine candidate based on this unnatural glycopeptide and conjugated to the carrier protein Keyhole Limpet Hemocyanin (KLH) has been prepared and tested in mice. Significantly, the experiments in vivo have proved that this vaccine elicits higher levels of specific anti-MUC1 IgG antibodies than the analog that bears the natural Tn antigen and that the elicited antibodies recognize human breast cancer cells with high selectivity. Altogether, we compile evidence to confirm that the presentation of the antigen, both in solution and in the bound state, plays a critical role in the efficacy of the designed cancer vaccines. Moreover, the outcomes derived from this vaccine prove that there is room for exploring further adjustments at the carbohydrate level that could contribute to designing more efficient cancer vaccines.

18.
Molecules ; 24(16)2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31398901

RESUMO

The unique stereoelectronic properties of sp2-iminosugars enable their participation in glycosylation reactions, thereby behaving as true carbohydrate chemical mimics. Among sp2-iminosugar conjugates, the sp2-iminosugar glycolipids (sp2-IGLs) have shown a variety of interesting pharmacological properties ranging from glycosidase inhibition to antiproliferative, antiparasitic, and anti-inflammatory activities. Developing strategies compatible with molecular diversity-oriented strategies for structure-activity relationship studies was therefore highly wanted. Here we show that a reaction sequence consisting in stereoselective C-allylation followed by thiol-ene "click" coupling provides a very convenient access to α-C-glycoside sp2-IGLs. Both the glycone moiety and the aglycone tail can be modified by using sp2-iminosugar precursors with different configurational profiles (d-gluco or d-galacto in this work) and varied thiols, as well as by oxidation of the sulfide adducts (to the corresponding sulfones in this work). A series of derivatives was prepared in this manner and their glycosidase inhibitory, antiproliferative and antileishmanial activities were evaluated in different settings. The results confirm that the inhibition of glycosidases, particularly α-glucosidase, and the antitumor/leishmanicidal activities are unrelated. The data are also consistent with the two later activities arising from the ability of the sp2-IGLs to interfere in the immune system response in a cell line and cell context dependent manner.


Assuntos
Química Click , Glicolipídeos/síntese química , Glicolipídeos/farmacologia , Glicosídeos/química , Imino Açúcares/química , Compostos de Sulfidrila/química , Antiprotozoários/síntese química , Antiprotozoários/farmacologia , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Glicolipídeos/química , Glicosídeo Hidrolases/antagonistas & inibidores , Glicosídeo Hidrolases/química , Humanos , Testes de Sensibilidade Parasitária
19.
Eur J Med Chem ; 182: 111604, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31425910

RESUMO

Immunomodulatory glycolipids, among which α-galactosylceramide (KRN7000) is an iconic example, have shown strong therapeutic potential in a variety of conditions ranging from cancer and infection to autoimmune or neurodegenerative diseases. A main difficulty for those channels is that they often provoke a cytokine storm comprising both pro- and anti-inflammatory mediators that antagonize each other and negatively affect the immune response. The synthesis of analogues with narrower cytokine secretion-inducing capabilities is hampered by the intrinsic difficulty at controlling the stereochemical outcome in glycosidation reactions, particularly if targeting the α-anomer, which seriously hampers drug optimization strategies. Here we show that replacing the monosaccharide glycone by a sp2-iminosugar glycomimetic moiety allows accessing N-linked sp2-iminosugar glycolipids (sp2-IGLs) with total α-stereocontrol in a single step with no need of protecting groups or glycosidation promotors. The lipid tail has been then readily tailored by incorporating polyfluoroalkyl segments of varied lengths in view of favouring binding to the lipid binding site of the master p38 mitogen activated protein kinase (p38 MAPK), thereby polarizing the immune response in a cell-context dependent manner. The compounds have been evaluated for their antiproliferative, anti-leishmanial and anti-inflammatory activities in different cell assays. The size of the fluorous segment was found to be critical for the biological activity, probably by regulating the aggregation and membrane-crossing properties, whereas the hydroxylation profile (gluco or galacto-like) was less relevant. Biochemical and computational data further support a mechanism of action implying binding to the allosteric lipid binding site of p38 MAPK and subsequent activation of the noncanonical autophosphorylation route. The ensemble of results provide a proof of concept of the potential of sp2-IGLs as immunoregulators.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Antineoplásicos/farmacologia , Antiprotozoários/farmacologia , Leishmania/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Animais , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Antineoplásicos/síntese química , Antineoplásicos/química , Antiprotozoários/síntese química , Antiprotozoários/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Glicolipídeos/síntese química , Glicolipídeos/química , Glicolipídeos/farmacologia , Humanos , Imino Açúcares/síntese química , Imino Açúcares/química , Imino Açúcares/farmacologia , Fatores Imunológicos/síntese química , Fatores Imunológicos/química , Fatores Imunológicos/farmacologia , Camundongos , Simulação de Acoplamento Molecular , Estrutura Molecular , Testes de Sensibilidade Parasitária , Fosforilação/efeitos dos fármacos , Relação Estrutura-Atividade , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
20.
Eur J Med Chem ; 169: 111-120, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30870792

RESUMO

Glycolipid mimetics consisting of a bicyclic polyhydroxypiperidine-cyclic carbamate core and a pseudoanomeric hydrophobic tail, termed sp2-iminosugar glycolipids (sp2-IGLs), target microglia during neuroinflammatory processes. Here we have synthesized and investigated new variants of sp2-IGLs for their ability to suppress the activation of human monocyte-derived dendritic cells (DCs) by lipopolysaccharide (LPS) signaling through Toll-like receptor 4. We report that the best lead was (1R)-1-dodecylsulfonyl-5N,6O-oxomethylidenenojirimycin (DSO2-ONJ), able to inhibit LPS-induced TNFα production and maturation of DCs. Immunovisualization experiments, using a mannoside glycolipid conjugate (MGC) that also suppress LPS-mediated DC activation as control, evidenced a distinct mode of action for the sp2-IGLs: unlike MGCs, DSO2-ONJ did not elicit internalization of the LPS co-receptor CD14 or induce its co-localization with the Toll-like receptor 4. In a mouse model of LPS-induced acute inflammation, DSO2-ONJ demonstrated anti-inflammatory activity by inhibiting the production of the pro-inflammatory interleukin-6. The ensemble of the data highlights sp2-IGLs as a promising new class of molecules against inflammation by interfering in Toll-like receptor intracellular signaling.


Assuntos
Glicolipídeos/farmacologia , Inflamação/tratamento farmacológico , Lipopolissacarídeos/antagonistas & inibidores , Doença Aguda , Animais , Células Cultivadas , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Relação Dose-Resposta a Droga , Glicolipídeos/síntese química , Glicolipídeos/química , Humanos , Inflamação/metabolismo , Inflamação/patologia , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estrutura Molecular , Relação Estrutura-Atividade
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