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Stem/progenitor cell therapy is a promising treatment option for patients with type 1 diabetes (T1D) a disease characterized by autoimmune destruction of pancreatic ß cells. Actively injecting cells into an organ is one option for cell delivery, but in the pancreas, this contributes to acute inflammation and pancreatitis. We employed a patch grafting approach to transplant biliary tree stem cells/progenitor cells (BTSC) onto the surface of the pancreas in diabetic mice. The cells engraft and differentiate into ß-like cells reversing hyperglycemia during a four-month period of observation. In addition, C-peptide and insulin gradually increase in blood circulation without detectable adverse effects during this period. Moreover, the patch graft transplant promoted the proliferation and differentiation of pancreatic ß-like cells with co-expression of the ß cell biomarker. CONCLUSION: BTSC transplantation can effectively attenuate T1D over a four-month period that is vital important for clinical applications.
Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Humanos , Camundongos , Animais , Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Experimental/metabolismo , Pâncreas/metabolismo , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Diferenciação CelularRESUMO
OBJECTIVE: To study the mechanism of renal injury in Lepr db/ db mice with the leptin receptor homozygous deficiency. METHODS: Ten male of 28-week-old Lepr db/+ mice with leptin receptor heterozygous deficiency were selected as control group and ten male Lepr db/ db mice with leptin receptor homozygous deficiency were used in this study. After fasting for 8 hours, the body mass, fasting blood glucose (FBG) and glycosylated hemoglobulin (HbA1c) of the mice were measured. Blood of the mice was obtained from femoral artery before euthanasia. Serum creatinine (CRE), blood urea nitrogen (BUN), superoxide dismutase (SOD), glutathione (GSH) and malonaldehyde (MDA) were detected by corresponding kits, and serum interleukin-1ß (IL-1ß), monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α) were measured using enzyme-linked immunosorbent assay (ELISA) method. The kidney was taken for pathological observation. The expression levels of nuclear factor E2-related factor 2 (Nrf2) and nuclear factor kappa B (NF-κB) in renal were analyzed by Western blot. The mitochondria of renal was isolated by the corresponding kit. Meanwhile, the expression level of lipoic acid synthase (LIAS) in renal mitochondria was measured by Western blot. RESULTS: The body mass, FPG, HbA1c, CRE and BUN levels of the Lepr db/ db mice were significantly increased in comparison with the Lepr db/+ mice ( P<0.05). Compared with the Lepr db/+ mice, the Lepr db/ db mice renal exhibited glomerular hypertrophy, thickened basement membrane and capillary wall, the mesangial matrix expansion and mesangial cell hyperplasia. Compared with the Lepr db/+ mice, the serum level of GSH in the Lepr db/ db mice was decreased significantly ( P<0.05). The levels of MDA and concentrations of MCP-1, IL-1ß and TNF-α in serum of the Lepr db/ db mice were higher than those of the Lepr db/+ mice ( P<0.05). Compared with the Lepr db/+ mice, the expression of LIAS and Nrf2 protein in the Lepr db/ db mice renal were decreased ( P<0.05), while the expression of NF-κB protein was increased ( P<0.05). CONCLUSION: LIAS, Nrf2 and NF-κB might play significant roles through regulation of oxidative stress and inflammation in the renal injury of Lepr db/ db mice.
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Rim/patologia , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Receptores para Leptina/genética , Sulfurtransferases/metabolismo , Animais , Masculino , Camundongos , Camundongos Knockout , Estresse OxidativoRESUMO
BACKGROUND: S-nitrosylation of mitochondrial enzymes involved in energy transfer under nitrosative stress may result in ATP deficiency. We investigated whether α-lipoic acid, a powerful antioxidant, could alleviate nitrosative stress by regulating S-nitrosylation, which could result in retaining the mitochondrial enzyme activity. METHODS: In this study, we have identified the S-nitrosylated forms of subunit 1 of dihydrolipoyllysine succinyltransferase (complex III), and subunit 2 of the α-ketoglutarate dehydrogenase complex by implementing a fluorescence-based differential quantitative proteomics method. RESULTS: We found that the activities of these two mitochondrial enzymes were partially but reversibly inhibited by S-nitrosylation in cultured endothelial cells, and that their activities were partially restored by supplementation of α-lipoic acid. We show that protein S-nitrosylation affects the activity of mitochondrial enzymes that are central to energy supply, and that α-lipoic acid protects mitochondrial enzymes by altering S-nitrosylation levels. CONCLUSIONS: Inhibiting protein S-nitrosylation with α-lipoic acid seems to be a protective mechanism against nitrosative stress. GENERAL SIGNIFICANCE: Identification and characterization of these new protein targets should contribute to expanding the therapeutic power of α-lipoic acid and to a better understanding of the underlying antioxidant mechanisms.
Assuntos
Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Complexo Cetoglutarato Desidrogenase/metabolismo , Óxido Nítrico/metabolismo , Estresse Oxidativo , Ácido Tióctico/farmacologia , Trifosfato de Adenosina/biossíntese , Animais , Células Cultivadas , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismoRESUMO
Carbon nanodots (CNDs) are a new type of nanomaterial with a size of less than 10 nanometers and excellent biocompatibility, widely used in fields such as biological imaging, transmission, diagnosis, and drug delivery. However, its potential and mechanism to mediate endothelial inflammation have yet to be explored. Here, we report that the uptake of CNDs by EA.hy926 endothelial cells is both time and dose dependent. The concentration of CNDs used in this experiment was found to not affect cell viability. TNF-α is a known biomarker of vascular inflammation. Cells treated with CNDs for 24 h significantly inhibited TNF-α (0.5 ng/mL)-induced expression of intracellular adhesion molecule 1 (ICAM-1) and interleukin 8 (IL-8). ICAM-1 and IL-8 are two key molecules responsible for the activation and the firm adhesion of monocytes to activated endothelial cells for the initiation of atherosclerosis. ROS, such as hydrogen peroxide, play an important role in TNF-α-induced inflammation. Interestingly, we found that CNDs effectively scavenged H2O2 in a dose-dependent manner. CNDs treatment also increased the activity of the antioxidant enzyme NQO1 in EA.hy926 endothelial cells indicating the antioxidant properties of CNDs. These results suggest that the anti-inflammatory effects of CNDs may be due to the direct H2O2 scavenging properties of CNDs and the indirect upregulation of antioxidant enzyme NQO1 activity in endothelial cells. In conclusion, CND can inhibit TNF-α-induced endothelial inflammation, possibly due to its direct scavenging of H2O2 and the indirect upregulation of antioxidant enzyme NQO1 activity in endothelial cells.
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Diabetes is a major risk factor for cardiovascular disease. To examine how diabetes interacts with a mildly compromised lipid metabolism, we introduced the diabetogenic Ins2(C96Y/+) (Akita) mutation into mice expressing human apoE4 (E4) combined with either an overexpressing human LDL receptor gene (hLDLR) or the wild-type mouse gene. The hLDLR allele caused 2-fold reductions in plasma HDL-cholesterol, plasma apoA1, and hepatic triglyceride secretion. Diabetes increased plasma total cholesterol 1.3-fold and increased apoB48 secretion 3-fold, while reducing triglyceride secretion 2-fold. Consequently, diabetic E4 mice with hLDLR secrete increased numbers of small, cholesterol-enriched, apoB48-containing VLDL, although they have near normal plasma cholesterol (<120 mg/dl). Small foam cell lesions were present in the aortic roots of all diabetic E4 mice with hLDLR that we analyzed at six months of age. None were present in nondiabetic mice or in diabetic mice without hLDLR. Aortic expression of genes affecting leukocyte recruitment and adhesion was enhanced by diabetes. ApoA1 levels, but not diabetes, were strongly correlated with the ability of plasma to efflux cholesterol from macrophages. We conclude that the diabetes-induced proinflammatory changes in the vasculature and the hLDLR-mediated cholesterol accumulation in macrophages synergistically trigger atherosclerosis in mice with human apoE4, although neither alone is sufficient.
Assuntos
Apolipoproteína E4/genética , Aterosclerose/metabolismo , Complicações do Diabetes/metabolismo , Complicações do Diabetes/patologia , Angiopatias Diabéticas/metabolismo , Lipoproteínas/metabolismo , Alelos , Animais , Aterosclerose/genética , Aterosclerose/patologia , Transporte Biológico , Colesterol/metabolismo , Complicações do Diabetes/genética , Angiopatias Diabéticas/genética , Angiopatias Diabéticas/patologia , Regulação da Expressão Gênica , Humanos , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Lipoproteínas/sangue , Lipoproteínas VLDL/metabolismo , Fígado/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Receptores de LDL/genéticaRESUMO
Herein we report the development of a nonviral lipid-complexed PRINT (particle replication in nonwetting templates) protein particle system (LPP particle) for RNA replicon delivery with a view toward RNA replicon-based vaccination. Cylindrical bovine serum albumin (BSA) particles (diameter (d) 1 µm, height (h) 1 µm) loaded with RNA replicon and stabilized with a fully reversible disulfide cross-linker were fabricated using PRINT technology. Highly efficient delivery of the particles to Vero cells was achieved by complexing particles with a mixture of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) lipids. Our data suggest that (1) this lipid-complexed protein particle is a promising system for delivery of RNA replicon-based vaccines and (2) it is necessary to use a degradable cross-linker for successful delivery of RNA replicon via protein-based particles.
Assuntos
Lipídeos/química , RNA/genética , Linhagem Celular , Ácidos Graxos Monoinsaturados/química , Técnicas de Transferência de Genes , Humanos , Fosfatidiletanolaminas/química , Compostos de Amônio Quaternário/química , RNA/administração & dosagem , RNA/química , Soroalbumina Bovina/químicaRESUMO
Oxidative stress contributes to the pathogenesis of diabetic nephropathy. In mitochondria, lipoic acid synthase produces α-lipoic acid, an antioxidant and an essential cofactor in α-ketoacid dehydrogenase complexes, which participate in glucose oxidation and ATP generation. Administration of lipoic acid abrogates diabetic nephropathy in animal models, but whether lower production of endogenous lipoic acid promotes diabetic nephropathy is unknown. Here, we crossed mice heterozygous for lipoic acid synthase deficiency (Lias(+/-)) with Ins2(Akita/+) mice, a well characterized model of type 1 diabetes. Double mutant mice had more overt diabetic nephropathy, including microalbuminuria, glomerular basement thickening, mesangial matrix expansion, and hypertension, compared with Lias(+/+)Ins2(Akita/+) controls. We also identified proximal tubules as a major site for generation of superoxide anions during diabetic nephropathy. Mitochondria in proximal tubular cells were particularly sensitive to damage in diabetic mice with reduced lipoic acid production. These results suggest that lipoic acid synthase deficiency increases oxidative stress and accelerates the development of diabetic nephropathy.
Assuntos
Nefropatias Diabéticas/enzimologia , Estresse Oxidativo , Sulfurtransferases/metabolismo , Animais , Glicemia/metabolismo , Citrato (si)-Sintase/metabolismo , Nefropatias Diabéticas/sangue , Nefropatias Diabéticas/complicações , Nefropatias Diabéticas/patologia , Expressão Gênica , Hipertensão/etiologia , Túbulos Renais Proximais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fenótipo , Superóxidos/metabolismoRESUMO
Patch grafting, a novel strategy for transplantation of stem/progenitor organoids into porcine livers, has been found successful also for organoid transplantation into other normal or diseased solid organs in pigs and mice. Each organoid contained â¼100 cells comprised of biliary tree stem cells (BTSCs), co-hepato/pancreatic stem/progenitors, and partnered with early lineage stage mesenchymal cells (ELSMCs), angioblasts and precursors to endothelia and stellate cells. Patch grafting enabled transplantation into livers or pancreases of ≥108th (pigs) or ≥106th-7th (mice) organoids/patch. Graft conditions fostered expression of multiple matrix-metalloproteinases (MMPs), especially secretory isoforms, resulting in transient loss of the organ's matrix-dictated histological features, including organ capsules, and correlated with rapid integration within a week of organoids throughout the organs and without emboli or ectopic cell distribution. Secondarily, within another week, there was clearance of graft biomaterials, followed by muted expression of MMPs, restoration of matrix-dictated histology, and maturation of donor cells to functional adult fates. The ability of patch grafts of organoids to rescue hosts from genetic-based disease states was demonstrated with grafts of BTSC/ELSMC organoids on livers, able to rescue NRG/FAH-KO mice from type I tyrosinemia, a disease caused by absence of fumaryl acetoacetate hydrolase. With the same grafts, if on pancreas, they were able to rescue NRG/Akita mice from type I diabetes, caused by a mutation in the insulin 2 gene. The potential of patch grafting for cell therapies for solid organs now requires translational studies to enable its adaptation and uses for clinical programs.
Assuntos
Sistema Biliar , Organoides , Animais , Fígado , Camundongos , Organoides/metabolismo , Pâncreas/metabolismo , Células-Tronco/metabolismo , SuínosRESUMO
Oxidative stress is proposed to be involved in nonalcoholic fatty liver disease (NAFLD). However, antioxidant therapy results in controversial outcomes. Therefore, we generated a new antioxidant/NAFLD mouse model, LiasHigh/HighLeprdb/db mice, by crossbreeding Leprdb/db mice, an obesity mouse model, with LiasHigh/High mice, generated by overexpression of lipoic acid synthase gene (Lias) and having increased endogenous antioxidant capacity, to investigate whether the new model could block the development of NAFLD. We have systemically characterized the novel model based on the main features of human NAFLD, determined the impact of enhanced endogenous antioxidant capacity on the retardation of NAFLD and elucidated the underlying mechanisms using various biological and pathological methods. We found that LiasHigh/HighLeprdb/db mice ameliorated many pathological changes of NAFLD compared with the control. In particular, LiasHigh/HighLeprdb/db mice displayed the improved liver mitochondrial function, reflecting the decline of mitochondrial microvesicular steatosis, and reduced oxidative stress, which mainly contributes to the alleviation of pathologic alterations of the NAFLD progression. Our new model shows that mitochondrial dysfunction is a major pathogenesis for liver steatosis. Overexpression of Lias gene effectively reduces oxidative stress and protects mitochondria, and consequently attenuates NAFLD/NASH.
Assuntos
Hepatopatia Gordurosa não Alcoólica/metabolismo , Sulfurtransferases/metabolismo , Animais , Antioxidantes/metabolismo , Metabolismo dos Carboidratos , Modelos Animais de Doenças , Feminino , Metabolismo dos Lipídeos , Masculino , Camundongos Endogâmicos C57BL , Mitocôndrias Hepáticas/metabolismo , Mitocôndrias Hepáticas/ultraestrutura , Hepatopatia Gordurosa não Alcoólica/patologia , Receptores para Leptina/genética , Sulfurtransferases/genéticaRESUMO
INTRODUCTION: Diabetic nephropathy (DN) develops in about 40% of patients with type 2 diabetes and remains the leading cause of end-stage renal disease. The mechanisms of DN remain to be elucidated. Oxidative stress is thought to be involved in the development of DN but antioxidant therapy has produced conflicting results. Therefore, we sought to define the role of antioxidant in retarding the development of DN in this study. RESEARCH DESIGN AND METHODS: We generated a new antioxidant/diabetes mouse model, LiasH/HLeprdb/db mice, by crossing db/db mice with LiasH/H mice, which have overexpressed Lias gene (~160%) compared with wild type, and also correspondingly increased endogenous antioxidant capacity. The new model was used to investigate whether predisposed increased endogenous antioxidant capacity was able to retard the development of DN. We systemically and dynamically examined main pathological alterations of DN and antioxidant biomarkers in blood and kidney mitochondria. RESULTS: LiasH/HLeprdb/db mice alleviated major pathological alterations in the early stage of DN, accompanied with significantly enhanced antioxidant defense. The model targets the main pathogenic factors by exerting multiple effects such as hypoglycemic, anti-inflammation, and antioxidant, especially protection of mitochondria. CONCLUSION: The antioxidant animal model is not only very useful for elucidating the underlying mechanisms of DN but also brings insight into a new therapeutic strategy for clinical applications.
Assuntos
Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Animais , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/genética , Nefropatias Diabéticas/genética , Humanos , Rim , Camundongos , SulfurtransferasesRESUMO
Atherosclerosis represents an ever-present global concern, as it is a leading cause of cardiovascular disease and an immense public welfare issue. Macrophages play a key role in the onset of the disease state and are popular targets in vascular research and therapeutic treatment. Carbon nanodots (CNDs) represent a type of carbon-based nanomaterial and have garnered attention in recent years for potential in biomedical applications. This investigation serves as a foremost attempt at characterizing the interplay between macrophages and CNDs. We have employed THP-1 monocyte-derived macrophages as our target cell line representing primary macrophages in the human body. Our results showcase that CNDs are non-toxic at a variety of doses. THP-1 monocytes were differentiated into macrophages by treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA) and co-treatment with 0.1 mg/mL CNDs. This co-treatment significantly increased the expression of CD 206 and CD 68 (key receptors involved in phagocytosis) and increased the expression of CCL2 (a monocyte chemoattractant and pro-inflammatory cytokine). The phagocytic activity of THP-1 monocyte-derived macrophages co-treated with 0.1 mg/mL CNDs also showed a significant increase. Furthermore, this study also examined potential entrance routes of CNDs into macrophages. We have demonstrated an inhibition in the uptake of CNDs in macrophages treated with nocodazole (microtubule disruptor), N-phenylanthranilic acid (chloride channel blocker), and mercury chloride (aquaporin channel inhibitor). Collectively, this research provides evidence that CNDs cause functional changes in macrophages and indicates a variety of potential entrance routes.
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Oxidized low density lipoprotein (Ox-LDL) is a known biomarker of inflammation and atherosclerosis, a leading cause of death worldwide. As a new class of nanomaterials, carbon nanodots (CNDs) are widely used in bioimaging, diagnostics, and drug delivery. However, there is no current report on how these CNDs affect the cardiovascular system, particularly their potential in mediating endothelial inflammatory dysfunction. This study examined effects of CNDs on Ox-LDL-mediated endothelial dysfunction. CNDs significantly inhibited Ox-LDL-mediated adhesion of monocytes to human microvascular endothelial cells (HMEC-1), in human microvascular endothelial cells (HMEC-1). CNDs significantly inhibited Ox-LDL-mediated adhesion of monocytes to endothelial cells, which is an essential step in the development of atherosclerosis. Further, CNDs significantly inhibited OxLDL-induced expression of interleukin-8 (IL-8), a vital cytokine on monocyte adhesion to the endothelial cells. These results demonstrate CNDs possess anti-inflammatory properties. CNDs also protect cells against Ox-LDL-induced cytotoxicity. Electron paramagnetic resonance (EPR) spectroscopy studies demonstrated direct reactive oxygen species-scavenging by CNDs. This result indicates that the anti-inflammatory properties of CNDs are most likely due to their direct scavenging of reactive oxygen species. Animal studies involving mice did not show any morphological or physical changes between the CNDs and control groups. Our study provides evidence of potential of CNDs in reducing Ox-LDL-mediated inflammation and cytotoxicity in HMEC-1.
Assuntos
Células Endoteliais , Monócitos , Animais , Carbono , Lipoproteínas LDL , Camundongos , Espécies Reativas de OxigênioRESUMO
Epithelial cell therapies have been at an impasse because of inefficient methods of transplantation to solid organs. Patch grafting strategies were established enabling transplantation of ≥107th organoids/patch of porcine GFP+ biliary tree stem/progenitors into livers of wild type hosts. Grafts consisted of organoids embedded in soft (~100 Pa) hyaluronan hydrogels, both prepared in serum-free Kubota's Medium; placed against target sites; covered with a silk backing impregnated with more rigid hyaluronan hydrogels (~700 Pa); and use of the backing to tether grafts with sutures or glue to target sites. Hyaluronan coatings (~200-300 Pa) onto the serosal surface of the graft served to minimize adhesions with neighboring organs. The organ's clearance of hyaluronans enabled restoration of tissue-specific paracrine and systemic signaling, resulting in return of normal hepatic histology, with donor parenchymal cells uniformly integrated amidst host cells and that had differentiated to mature hepatocytes and cholangiocytes. Grafts containing donor mature hepatocytes, partnered with endothelia, and in the same graft biomaterials as for stem/progenitor organoids, did not engraft. Engraftment occurred if porcine liver-derived mesenchymal stem cells (MSCs) were co-transplanted with donor mature cells. RNA-seq analyses revealed that engraftment correlated with expression of matrix-metalloproteinases (MMPs), especially secreted isoforms that were found expressed strongly by organoids, less so by MSCs, and minimally, if at all, by adult cells. Engraftment with patch grafting strategies occurred without evidence of emboli or ectopic cell distribution. It was successful with stem/progenitor organoids or with cells with a source(s) of secreted MMP isoforms and offers significant potential for enabling cell therapies for solid organs.
Assuntos
Fígado , Organoides , Animais , Diferenciação Celular , Hepatócitos , Células-Tronco , SuínosRESUMO
Alpha-lipoic acid (1, 2-dithiolane-3-pentanoic acid; LA), synthesized in mitochondria by LA synthase (Lias), is a potent antioxidant and a cofactor for metabolic enzyme complexes. In this study, we examined the effect of genetic reduction of LA synthesis on its antioxidant and anti-inflammatory properties using a model of LPS-induced inflammation in Lias+/- mice. The increase of plasma proinflammatory cytokine, TNF-alpha, and NF-kappaB at an early phase following LPS injection was greater in Lias+/- mice compared with Lias+/+ mice. The circulating blood white blood cell (WBC) and platelet counts dropped continuously during the initial 4 h. The counts subsequently recovered partially in Lias+/+ mice, but the recovery was impaired totally in Lias+/- mice. Administration of exogenous LA normalized the recovery of WBC counts in Lias+/- mice but not platelets. Enhanced neutrophil sequestration in the livers of Lias+/- mice was associated with increased hepatocyte injury and increased gene expression of growth-related oncogene, E-selectin, and VCAM-1 in the liver and/or lung. Lias gene expression in tissues was 50% of normal expression in Lias+/- mice and reduced further by LPS treatment. Decreased Lias expression was associated with diminished hepatic LA and tissue oxidative stress. Finally, Lias+/- mice displayed enhanced mortality when exposed to LPS-induced sepsis. These data demonstrate the importance of endogenously produced LA for preventing leukocyte accumulation and tissue injury that result from LPS-induced inflammation.
Assuntos
Lipopolissacarídeos/farmacologia , Sepse/patologia , Sulfurtransferases/fisiologia , Ácido Tióctico/metabolismo , Animais , Citocinas/sangue , Selectina E/metabolismo , Metabolismo Energético , Heterozigoto , Fígado/efeitos dos fármacos , Fígado/patologia , Pulmão/efeitos dos fármacos , Pulmão/patologia , Camundongos , Camundongos Transgênicos , NF-kappa B/metabolismo , Estresse Oxidativo , Sepse/metabolismo , Sepse/mortalidade , Sulfurtransferases/genética , Ácido Tióctico/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismoRESUMO
We developed a vaccine formulation containing ApoB derived P210 peptides as autoantigens, retinoic acid (RA) as an immune enhancer, both of which were delivered using PLGA nanoparticles. The formula was used to induce an immune response in 12-week-old male Apoe-/- mice with pre-existing atherosclerotic lesions. The nanotechnology platform PRINT® was used to fabricate PLGA nanoparticles that encapsulated RA inside and adsorbed the P210 onto the particle surface. In this study, we demonstrated that immunization of Apoe-/- mice with the formulation was able to considerably attenuate atherosclerotic lesions, accompanied by increased P210 specific IgM and another oxidized lipid derived autoantigen, M2AA, specific IgG autoantibodies, and decreased the inflammatory response, as compared to the P210 group with Freund's adjuvant. Our formulation represents an exciting technology to enhance the efficacy of the P210 vaccine.
Assuntos
Aterosclerose , Nanopartículas , Animais , Apolipoproteína B-100 , Aterosclerose/tratamento farmacológico , Aterosclerose/prevenção & controle , Masculino , Camundongos , Peptídeos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , TretinoínaRESUMO
Atherosclerosis is a systemic chronic inflammatory disease. Many antioxidants including alpha-lipoic acid (LA), a product of lipoic acid synthase (Lias), have proven to be effective for treatment of this disease. However, the question remains whether LA regulates the immune response as a protective mechanism against atherosclerosis. We initially investigated whether enhanced endogenous antioxidant can retard the development of atherosclerosis via immunomodulation. To explore the impact of enhanced endogenous antioxidant on the retardation of atherosclerosis via immune regulation, our laboratory has recently created a double mutant mouse model, using apolipoprotein E-deficient (Apoe-/-) mice crossbred with mice overexpressing lipoic acid synthase gene (LiasH/H), designated as LiasH/HApoe-/- mice. Their littermates, Lias+/+Apoe-/- mice, served as a control. Distinct redox environments between the two strains of mice have been established and they can be used to facilitate identification of antioxidant targets in the immune response. At 6 months of age, LiasH/HApoe-/- mice had profoundly decreased atherosclerotic lesion size in the aortic sinus compared to their Lias+/+Apoe-/- littermates, accompanied by significantly enhanced numbers of regulatory T cells (Tregs) and anti-oxidized LDL autoantibody in the vascular system, and reduced T cell infiltrates in aortic walls. Our results represent a novel exploration into an environment with increased endogenous antioxidant and its ability to alleviate atherosclerosis, likely through regulation of the immune response. These outcomes shed light on a new therapeutic strategy using antioxidants to lessen atherosclerosis.
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Aorta/enzimologia , Doenças da Aorta/prevenção & controle , Aterosclerose/prevenção & controle , Placa Aterosclerótica , Sulfurtransferases/biossíntese , Animais , Aorta/imunologia , Aorta/patologia , Doenças da Aorta/enzimologia , Doenças da Aorta/imunologia , Doenças da Aorta/patologia , Aterosclerose/enzimologia , Aterosclerose/imunologia , Aterosclerose/patologia , Autoanticorpos/sangue , Modelos Animais de Doenças , Indução Enzimática , Lipoproteínas LDL/imunologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout para ApoE , Oxirredução , Estresse Oxidativo , Sulfurtransferases/genética , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismoRESUMO
We have previously reported that genetically increased angiotensin-converting enzyme levels, or absence of the bradykinin B2 receptor, increase kidney damage in diabetic mice. We demonstrate here that this is part of a more general phenomenon - diabetes and, to a lesser degree, absence of the B2 receptor, independently but also largely additively when combined, enhance senescence-associated phenotypes in multiple tissues. Thus, at 12 months of age, indicators of senescence (alopecia, skin atrophy, kyphosis, osteoporosis, testicular atrophy, lipofuscin accumulation in renal proximal tubule and testicular Leydig cells, and apoptosis in the testis and intestine) are virtually absent in WT mice, detectable in B2 receptor-null mice, clearly apparent in mice diabetic because of a dominant mutation (Akita) in the Ins2 gene, and most obvious in Akita diabetic plus B2 receptor-null mice. Renal expression of several genes that encode proteins associated with senescence and/or apoptosis (TGF-beta1, connective tissue growth factor, p53, alpha-synuclein, and forkhead box O1) increases in the same progression. Concomitant increases occur in 8-hydroxy-2'-deoxyguanosine, point mutations and deletions in kidney mitochondrial DNA, and thiobarbituric acid-reactive substances in plasma, together with decreases in the reduced form of glutathione in erythrocytes. Thus, absence of the bradykinin B2 receptor increases the oxidative stress, mitochondrial DNA damage, and many senescence-associated phenotypes already present in untreated Akita diabetic mice.
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Diabetes Mellitus/patologia , Receptor B2 da Bradicinina/genética , Receptor B2 da Bradicinina/fisiologia , 8-Hidroxi-2'-Desoxiguanosina , Animais , Apoptose , Senescência Celular , DNA Mitocondrial/metabolismo , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica , Genes Dominantes , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Estresse OxidativoRESUMO
alpha-Lipoic acid (LA) is a cofactor for mitochondrial alpha-ketoacid dehydrogenase complexes and is one of the most potent, natural antioxidants. Reduction of oxidative stress by LA supplementation has been demonstrated in patients with diabetic neuropathy and in animal models. To determine how normal development or pathological conditions are affected by genetic alterations in the ability of mammalian cells to synthesize LA and whether dietary LA can circumvent its endogenous absence, we have generated mice deficient in lipoic acid synthase (Lias). Mice heterozygous for disruption of the Lias gene develop normally, and their plasma levels of thiobarbituric acid-reactive substances do not differ from those of wild-type mice. However, the heterozygotes have significantly reduced erythrocyte glutathione levels, indicating that their endogenous antioxidant capacity is lower than those of wild-type mice. Homozygous embryos lacking Lias appear healthy at the blastocyst stage, but their development is retarded globally by 7.5 days postcoitum (dpc), and all the null embryos die before 9.5 dpc. Supplementing the diet of heterozygous mothers with LA (1.65 g/kg of body weight) during pregnancy fails to prevent the prenatal deaths of homozygous embryos. Thus, endogenous LA synthesis is essential for developmental survival and cannot be replaced by LA in maternal tissues and blood.
Assuntos
Desenvolvimento Embrionário , Sulfurtransferases/genética , Ácido Tióctico/biossíntese , Animais , Dieta , Embrião de Mamíferos/efeitos dos fármacos , Embrião de Mamíferos/metabolismo , Desenvolvimento Embrionário/efeitos dos fármacos , Desenvolvimento Embrionário/genética , Camundongos , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Ácido Tióctico/deficiência , Ácido Tióctico/farmacologiaRESUMO
Air pollution of particulate matter (PM), especially PM2.5, has become a major public health problem in China. Exploration of therapeutic and preventive measures against PM2.5 toxicity is of practical significance. The aim of this study was to examine the inhibitory effects of chitosan oligosaccharides (COS) on PM2.5-induced lung inflammation in rats. Forty SPF (specific pathogen-free) male Wistar rats weighing 200-220 g were randomly divided into four groups: control group, COS group, PM2.5 group, and PM2.5+COS group. COS was pre-administered to rats by gavage at a single dose of 500 mg/kg 2 h before intratracheal instillation of PM2.5 at a single dose of 1.2 mg/kg daily for 3 consecutive days. Normal saline (NS) was used as negative control. Twenty-four hours after the last instillation of PM2.5, rats were sacrificed and subjected to bronchoalveolar lavage (BAL). The BAL fluids (BALF) were collected for measurement of levels of total proteins, lactate dehydrogenase (LDH), interleukin-1 (IL-1ß), IL-8, and tumor necrosis factor-É (TNF-É) using colorimetric or ELISA kits. Levels of total proteins, LDH activities, and pro-inflammatory mediators including IL-1ß, IL-8, and TNF-É in BALF of rats in PM2.5 group significantly increased in comparison with those of the control group. Pre-treatment of rats with COS markedly blocked PM2.5-induced increase in LDH, IL-8, and TNF-É levels in BALF. In conclusion, PM2.5 exposure induces rat lung inflammation, which could be ameliorated by the pre-treatment of COS.
Assuntos
Quitosana/química , Oligossacarídeos/farmacologia , Material Particulado/toxicidade , Pneumonia/tratamento farmacológico , Poluentes Atmosféricos/toxicidade , Animais , Líquido da Lavagem Broncoalveolar , Interleucina-1beta/metabolismo , Interleucina-8/metabolismo , Lactato Desidrogenases/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/patologia , Masculino , Oligossacarídeos/química , Pneumonia/induzido quimicamente , Pneumonia/metabolismo , Ratos Wistar , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Considerable evidence indicates that hyperglycemia increases oxidative stress and contributes to the increased incidence of atherosclerosis and cardiovascular complications in diabetic patients. To examine the effect of alpha-lipoic acid, a potent natural antioxidant, on atherosclerosis in diabetic mice, 3-month-old apolipoprotein (apo) E-deficient (apoE(-/-)) mice were made diabetic by administering streptozotocin (STZ). At 4 weeks after starting the STZ administration, a high-fat diet with or without alpha-lipoic acid (1.65 g/kg) was given to the mice and to nondiabetic apoE(-/-) controls. At 20 weeks, markers of oxidative stress were significantly lower in both the diabetic apoE(-/-) mice and their nondiabetic apoE(-/-) controls with alpha-lipoic acid supplement than in those without it. Remarkably, alpha-lipoic acid completely prevented the increase in plasma total cholesterol, atherosclerotic lesions, and the general deterioration of health caused by diabetes. These protective effects of alpha-lipoic acid were accompanied by a reduction of plasma glucose and an accelerated recovery of insulin-producing cells in the pancreas, suggesting that part of its effects are attributable to protecting pancreatic beta-cells from damage. Our results suggest that dietary alpha-lipoic acid is a promising protective agent for reducing cardiovascular complications of diabetes.