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1.
Mol Cell Biochem ; 2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37402020

RESUMO

Obesity is closely associated with non-alcoholic fatty liver disease (NAFLD), characterized by hepatic fat accumulation and hepatocyte injury. Preclinical studies have shown exacerbated weight gain associated with an obesogenic gluten-containing diet. However, whether gluten affects obesity-induced hepatic lipid accumulation still remains unclear. We hypothesized that gluten intake could affect fatty liver development in high-fat diet (HFD)-induced obese mice. Thus, we aimed to investigate the impact of gluten intake on NAFLD in HFD-induced obese mice. Male apolipoprotein E-deficient (Apoe-/-) mice were fed with a HFD containing (GD) or not (GFD) vital wheat gluten (4.5%) for 10 weeks. Blood and liver were collected for further analysis. We found that gluten exacerbated weight gain, hepatic fat deposition, and hyperglycemia without affecting the serum lipid profile. Livers of the GD group showed a larger area of fibrosis, associated with the expression of collagen and MMP9, and higher expression of apoptosis-related factors, p53, p21, and caspase-3. The expression of lipogenic factors, such as PPARγ and Acc1, was more elevated and factors related to beta-oxidation, such as PPARα and Cpt1, were lower in the GD group compared to the GFD. Further, gluten intake induced a more significant expression of Cd36, suggesting higher uptake of free fatty acids. Finally, we found lower protein expression of PGC1α followed by lower activation of AMPK. Our data show that gluten-containing high-fat diet exacerbated NAFLD by affecting lipogenesis and fatty acid oxidation in obese Apoe-/- mice through a mechanism involving lower activation of AMPK.

2.
IUBMB Life ; 75(9): 732-742, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37086464

RESUMO

Beyond its actions on the nervous system, amitriptyline (AM) has been shown to lower inflammatory, angiogenic, and fibrogenic markers in a few pathological conditions in human and in experimental animal models. However, its effects on foreign body reaction (FBR), a complex adverse healing process, after biomedical material implantation are not known. We have evaluated the effects of AM on the angiogenic and fibrogenic components on a model of implant-induced FBR. Sponge disks were implanted subcutaneously in C57BL/6 mice, that were treated daily with oral administration of AM (5 mg/kg) for seven consecutive days in two protocols: treatment was started on the day of surgery and the implants were removed on the seventh day after implantation and treatment started 7 days after implantation and the implants removed 14 after implantation. None of the angiogenic (vessels, Vascular endothelial growth factor (VEGF), and interleukin-1ß (IL-1ß) or fibrogenic parameters (collagen, TGF-ß, and fibrous capsule) and giant cell numbers analyzed were attenuated by AM in 7-day-old implants. However, AM was able to downregulate angiogenesis and FBR in 14-day-old implants. The effects of AM described here expands its range of actions as a potential agent capable of attenuating fibroproliferative processes that may impair functionality of implantable devices.


Assuntos
Amitriptilina , Fator A de Crescimento do Endotélio Vascular , Camundongos , Animais , Humanos , Amitriptilina/farmacologia , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Camundongos Endogâmicos C57BL , Reação a Corpo Estranho/induzido quimicamente , Reação a Corpo Estranho/metabolismo , Reação a Corpo Estranho/patologia , Colágeno/metabolismo
3.
Exp Physiol ; 108(1): 146-157, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36459573

RESUMO

NEW FINDINGS: What is the central question of this study? Peritoneal injury can result in a persistent fibroproliferative process in the abdominal cavity, causing pain and loss of function of internal organs. This study aimed to demonstrate the use of sodium butyrate (NaBu) as a potential agent to attenuate peritoneal fibrosis induced by a synthetic matrix. What is the main finding and its importance? Our findings provide the first evidence that NaBu attenuates the inflammatory, angiogenesis and fibrogenesis axes involved in the formation of peritoneal fibrovascular tissue, indicating the potential of this compound to ameliorate peritoneal fibrosis. ABSTRACT: The aim of this study was to identify the bio-efficacy of sodium butyrate (NaBu) on preventing the development of peritoneal fibrovascular tissue induced by implantation of a synthetic matrix in the abdominal cavity. Polyether-polyurethane sponge discs were implanted in the peritoneal cavity of mice, which were treated daily with oral administration of NaBu (100 mg/kg). Control animals received water (100 µl). After 7 days, the implants were removed for assessment of inflammatory, angiogenic and fibrogenic markers. Compared with control values, NaBu treatment decreased mast cell recruitment/activation, inflammatory enzyme activities, levels of pro-inflammatory cytokines, and the proteins p65 and p50 of the nuclear factor-κB pathway. Angiogenesis, as determined by haemoglobin content, vascular endothelial growth factor levels and the number of blood vessels in the implant, was reduced by the treatment. In NaBu-treated animals, the predominant collagen present in the abdominal fibrovascular tissue was thin collagen, whereas in control implants it was thick collagen. Transforming growth factor-ß1 levels were also lower in implants of treated animals. Sodium butyrate downregulated the inflammatory, angiogenesis and fibrogenesis axes of the fibroproliferative tissue induced by the intraperitoneal synthetic matrix. This compound has potential to control/regulate chronic inflammation and adverse healing processes in the abdominal cavity.


Assuntos
Fibrose Peritoneal , Camundongos , Animais , Ácido Butírico/farmacologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Colágeno/metabolismo
4.
Eur J Pharmacol ; 934: 175255, 2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-36088982

RESUMO

BACKGROUND AND PURPOSE: Amitriptyline (AM) is a classical and typical tricyclic antidepressant drug. Despite its well-known effects on the nervous system, it has been described to work as a TLR4 antagonist and several clinical works suggested some unexpected cardiovascular effects. The role of amitriptyline on vascular tone is not clear, thus we hypothesized that amitriptyline has a double effect on vascular tone by both endothelial TLR4-dependent nitric oxide down-regulation and calcium channel blockade in smooth muscle cells. EXPERIMENTAL APPROACH: Changes in isometric tension were recorded on a wire myograph. NO production was evaluated by fluorescence microscopy and flow cytometry in the mouse aorta and EAhy926 cells using DAF fluorescence intensity. Calcium influx was evaluated in A7r5 cells by flow cytometry. Western blot was used to analyze eNOS and nNOS phosphorylation. KEY RESULTS: AM reduced PE-induced contraction by calcium influx diminution in smooth muscle cells (F/F0 = 225.6 ± 15.9 and 118.6 ± 17.6 to CT and AM, respectively). AM impaired Ach-dependent vasodilation (Emax = 95.8 ± 1.4; 78.1 ± 1.8; 60.4 ± 2.9 and -7.4 ± 1.0 for CT, 0.01, 0,1 and 1 µmol/L AM, respectively) through reduction of calcium influx and NO availability and TLR4 antagonism in a concentration-dependent manner. AM or TLR4 gene deletion significantly reduced NO production (Fluorescence = 9503 ± 871.7, 2561 ± 282, 4771 ± 728 and 1029 ± 103 to CT, AM, TLR4-/- and AM + TLR4-/-, respectively) by an increase in nNOSser852 and reduction in eNOSser1177 phosphorylation in endothelial cells. CONCLUSIONS AND IMPLICATIONS: Our data show that amitriptyline impaired vascular function through two different mechanisms: blockade of TLR4 in endothelial cells and consequent decrease in NO production and calcium influx reduction in smooth muscle and endothelial cells. We also suggest, for the first time, nNOS activity reduction by AM in non-neuronal cells.


Assuntos
Canais de Cálcio , Células Endoteliais , Camundongos , Animais , Amitriptilina/farmacologia , Receptor 4 Toll-Like , Óxido Nítrico/metabolismo , Endotélio Vascular , Cálcio/metabolismo , Antidepressivos Tricíclicos/farmacologia , Camundongos Endogâmicos C57BL , Vasodilatação , Miócitos de Músculo Liso/metabolismo
5.
Microvasc Res ; 139: 104277, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34752815

RESUMO

Implantation of biomedical/synthetic devices to replace and/or repair biological tissues very often induces an adverse healing response (scarce angiogenesis, excessive collagen deposition) which is detrimental to implant functionality and integration to host tissue. Interleukin-33/ST2 axis (IL-33/ST2) has been shown to modulate angiogenic and remodeling processes in several types of injuries. However, its effects on these processes after implantation of synthetic matrix have not been reported. Using synthetic matrix of polyether-polyurethane implanted subcutaneously in mice lacking ST2 receptor (ST2/KO), we characterized neovascularization and matrix remodeling in the fibrovascular tissue induced by the implants. Tissue accumulation was increased inside and around the implants in KO implants relative to the wild type (WT). More intense proliferative activity, using CDC 47 marker, was observed in KO implants compared with that of WT implants. Angiogenesis, using two endothelial cell markers, Von Willebrand Factor (VWF) and vascular endothelial cell VE cadherin and hemoglobin content, increased in implants of KO mice relative to control WT. Remodeling of the newly formed fibrovascular tissue (soluble collagen and PicroSirius Red-stained histological sections) showed predominance of type 1 collagen in ST2-KO implants versus type 3 in control implants. The number of positive cells for caspase-3, apoptotic marker, decreased in ST2 group. Our findings evidenced a role of IL-33/ST2 axis in restraining blood vessel formation and regulating the pattern of matrix remodeling in the fibrovascular tissue induced by synthetic implants. Intervention in this cytokine complex holds potential to accelerate integration of biomaterial and host tissue by improving blood supply and matrix remodeling.


Assuntos
Matriz Extracelular/metabolismo , Reação a Corpo Estranho/metabolismo , Mediadores da Inflamação/metabolismo , Proteína 1 Semelhante a Receptor de Interleucina-1/deficiência , Interleucina-33/metabolismo , Neovascularização Fisiológica , Tela Subcutânea/metabolismo , Cicatrização , Animais , Colágeno Tipo I/metabolismo , Modelos Animais de Doenças , Matriz Extracelular/patologia , Fibrose , Reação a Corpo Estranho/etiologia , Reação a Corpo Estranho/genética , Reação a Corpo Estranho/patologia , Deleção de Genes , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Masculino , Camundongos Endogâmicos BALB C , Camundongos Knockout , Polietilenoglicóis , Poliuretanos , Transdução de Sinais , Tela Subcutânea/patologia , Tampões de Gaze Cirúrgicos , Fator A de Crescimento do Endotélio Vascular/metabolismo
6.
Inflammation ; 44(2): 580-591, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33034827

RESUMO

Recent data has signaled that in addition to its therapeutic indications as antidepressant and analgesic, amitriptyline (AM) exerts anti-inflammatory effects in humans and experimental animal models of acute inflammation. We tested the hypothesis that this compound could also modulate the chronic inflammatory process induced by synthetic matrix in mice. Polyether-polyurethane sponge disks were implanted subcutaneously in 9-week-old male C57BL/6 mice. The animals received by oral gavage 5.0 mg/kg of amitriptyline for seven consecutive days in two treatment regimens. In the first series, the treatment was initiated on the day of surgery and the implants removed at day 7 post-implantation. For the assessment of the effect of amitriptyline on chronic inflammation, the treatment was initiated 7 days post-implantation and the sponge discs removed 14 after implantation. The inflammatory markers evaluated, myeloperoxidase - MPO, nitrite content, IL-6, IFN-γ, TNF-α, CXCL1 and CCL2 levels, and NF-κB transcription factor activation were reduced in implants when the treatment began 7 days post-implantation (chronic inflammation). In contrast, only mast cell number, MPO activity and activation of NF-κB pathway decreased when the treatment began soon after implantation (sub-acute inflammation) in 7-day old implants. The anti-inflammatory effects of amitriptyline described here, extend its range of actions as a potential agent able to attenuate long-term inflammatory processes.


Assuntos
Amitriptilina/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Materiais Biocompatíveis/efeitos adversos , Inflamação/tratamento farmacológico , Poliuretanos/efeitos adversos , Animais , Biomarcadores/metabolismo , Western Blotting , Doença Crônica , Citocinas/metabolismo , Regulação para Baixo , Inflamação/diagnóstico , Inflamação/etiologia , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Resultado do Tratamento
7.
Acta Cir Bras ; 35(11): e301105, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33331455

RESUMO

PURPOSE: To assess the action of pentoxifylline, administered by subcutaneous route, on skin flap tissue repair in rats, and to verify the histological aspects and biomarkers. METHODS: Thirty-two male Wistar rats were divided into four groups: control (CT) and treated with pentoxifylline (P1, P3 and P5). Modified McFarlane technique flap was used. Ten days later, the animals were euthanized and the areas of viable and necrotic tissue were evaluated. Hematoxylin/eosin staining was used to assess the morphometric characteristics of the number of vessels and epithelial thickness. Picrosirius red was used to assess collagen density. VEGF and TGF-?1 levels on the skin flap and serum of the animals were measured by the ELISA method. RESULTS: The macroscopic evaluation of the skin flap dimensions showed reduced necrotic tissue in the pentoxifylline (p < 0.05) treated groups. There was an increase in angiogenesis and reepithelization, demonstrated by analyses with an increased number of vessels (p < 0.05), VEGF and epithelial thickness. Fibrogenic effect showed decreased collagen density and TGF-ß1 in the skin flap and serum. CONCLUSION: The benefits of pentoxifylline administered by subcutaneous route, at dose 100 mg/kg, which was effective to improve the survival of skin flap by acting on tissue repair components, stimulating angiogenesis and reepithelization, in addition to reducing fibrogenesis.


Assuntos
Pentoxifilina , Animais , Sobrevivência de Enxerto , Masculino , Necrose , Pentoxifilina/farmacologia , Ratos , Ratos Wistar , Transplante de Pele , Retalhos Cirúrgicos
8.
Microvasc Res ; 131: 104014, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32450153

RESUMO

The damaging effects of obesity extend to multiple pre-existing tissue/organs. However, the influence of this condition on key components (inflammation and angiogenesis) of fibrovascular connective proliferating tissue, essential in repair processes, has been neglected. Our objective in this study was to investigate whether obesity would influence inflammatory-angiogenesis induced by synthetic matrix of polyether-polyurethane implanted subcutaneously in high-fat-fed obese C57/BL6 mice. Fourteen days after implantation, the inflammatory and angiogenic components of the newly formed tissue intra-implant were evaluated. The pro-inflammatory enzyme activities, myeloperoxidase (MPO) and N-acetyl-ß-D-glucosaminidase (NAG), the levels of TNF-α, CXCL1/KC and CCL2 and NF-κB transcription factor were examined. Angiogenesis was determined by morphometric analysis of implant blood vessels, intra-implant levels of hemoglobin content, VEGF levels, and western blot for VEGFR2. All inflammatory and angiogenic markers were increased in the implants of obese mice compared with their non-obese counterparts. Similarly, activation of the NF-κB pathway and phosphorylation of VEGFR2 were higher in implants of obese mice (1.60 ± 0.28 Np65/Cp65; 0.96 ± 0.08 p-VEGFR2/VEGFR2-T) compared with implants of non-obese animals (1.40 ± 0.14; 0.49 ± 0.08). These observations suggest that obesity exerts critical role in sponge-induced inflammatory-angiogenesis, possibly by activating fibrovascular components in the inflamed microenvironment. Thus, this pathological condition causes damage not only to pre-existing tissues/organs but also to newly formed proliferating fibrovascular tissue. This is relevant to the development of therapeutic approaches to improve healing processes in patients with obesity.


Assuntos
Materiais Biocompatíveis , Reação a Corpo Estranho/etiologia , Mediadores da Inflamação/metabolismo , Inflamação/etiologia , Neovascularização Fisiológica , Obesidade/complicações , Polietilenoglicóis , Poliuretanos , Cicatrização , Animais , Dieta Hiperlipídica , Modelos Animais de Doenças , Reação a Corpo Estranho/metabolismo , Reação a Corpo Estranho/patologia , Reação a Corpo Estranho/fisiopatologia , Inflamação/metabolismo , Inflamação/patologia , Inflamação/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Obesidade/patologia , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
9.
Inflammation ; 43(4): 1259-1268, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32125592

RESUMO

Sodium butyrate (NaBu), a histone deacetylase inhibitor, has shown to exert beneficial actions attenuating inflammation in a number of intestinal and extra-intestinal diseases. However, the effects of NaBu on persistent inflammatory processes as in a response to implantation of foreign material have not been investigated. Synthetic matrix of polyether-polyurethane sponge was implanted in mice's subcutaneous layer of the dorsal region, and the animals were treated daily with oral administration of NaBu (100 mg/kg). After 7 days, the implants were removed and processed for assessment of inflammatory markers. Butyrate treatment caused a significant attenuation of neutrophil and macrophage infiltration in implants, which was reflected by the reduction of myeloperoxidase and N-acetyl-ß-D-glucosaminidase activities, respectively. Similar reduction was observed in intra-implants nitrite levels of NaBu-treated mice. NaBu treatment was also able to decrease mast cell recruitment/activation and the levels of CXCL1, CCL2, IL-6, TNF-ɑ, and TGF-ß1 in the implants but did not alter the levels of IL-10. In addition, NaBu administration decreased the concentration of proteins p65 and p50 in the nucleus as compared with the cytoplasm by western blot analysis. This result suggests that treatment with NaBu inhibited the NF-κB pathway. The circulating levels of TNF-ɑ and TGF-ß1 were also attenuated by NaBu. Persistent inflammation at sites of implanted devices very often impairs their functionality; therefore, our findings suggest that NaBu holds potential therapeutic value to control this adverse response to biomedical implants.


Assuntos
Ácido Butírico/uso terapêutico , Regulação para Baixo/efeitos dos fármacos , Antagonistas dos Receptores Histamínicos/uso terapêutico , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/metabolismo , Próteses e Implantes/efeitos adversos , Animais , Ácido Butírico/farmacologia , Regulação para Baixo/fisiologia , Éteres/administração & dosagem , Éteres/efeitos adversos , Antagonistas dos Receptores Histamínicos/farmacologia , Inflamação/tratamento farmacológico , Inflamação/etiologia , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Poliuretanos/administração & dosagem , Poliuretanos/efeitos adversos
10.
Inflammation ; 41(6): 2041-2051, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30069663

RESUMO

IL-33/ST2 axis has been shown to exert both pro- and anti- effects in wound healing and tumor development. To further understand the role of this cytokine complex, we characterized comparatively the inflammatory component of a malignant tissue and non-malignant tissue in mice lacking ST2 receptor (ST2-KO). KO mice and their wild-type (WT) counterparts were either implanted subcutaneously with polyether-polyurethane sponge discs to induce non-malignant fibrovascular tissue growth or inoculated with 4T1 cells to induce mammary tumor. Loss of ST2 receptor in mice resulted in enhanced mammary tumor and fibrovascular tissue relative to the WT animals. The inflammatory parameters (MPO and NAG activities, levels of the cytokines CXCL1/KC, CCL2, TNF-α, TGF-ß1, and mast cell number) were differentially modulated in both tissues. In tumors, these parameters were, overall, lower compared with those in tumors of WT mice. In KO implants, CXCL1/KC and TNF-α levels increased; MPO, NAG, and CCL2 levels decreased relative to the WT implants. In addition, deletion of ST2 receptor inhibited mast cell recruitment but had no effect on TGF-ß1 levels in implants. Our study has shown antitumorigenic effect of ST2 in mammary tumor and this may be mediated by downregulation of pro-inflammatory cytokines (CXCL1/KC, CCL2, TNF-α, and TGF-ß1). Conversely, in the fibrovascular tissue, lack of ST2 receptor resulted in differential modulation of cytokine production. Differential signaling mechanisms may be activated by IL-33/ST2 axis to modulate cytokine production in malignant and non-malignant proliferative processes.


Assuntos
Citocinas/biossíntese , Regulação Neoplásica da Expressão Gênica , Neoplasias/metabolismo , Animais , Neoplasias da Mama/metabolismo , Proteína 1 Semelhante a Receptor de Interleucina-1/deficiência , Interleucina-33 , Camundongos , Camundongos Knockout
11.
Biomed Pharmacother ; 106: 363-372, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29966982

RESUMO

Associations between obesity, diabetes type II, and steatosis have long been recognized. However, a pharmacotherapy that acts in a multifactorial manner controlling the interactions between these conditions is not available. A variety of natural plants, functional fatty acids, and other natural dietary compounds have been used in various anti-obesity products. We investigated the effects of oral administration of an antioxidant carotenoid pigment Bixin and Bixin: ß-Cyclodextrin in an obese murine model. C57BL/6 male mice (4-5 weeks) received standard diet (2.18 kcal per 1 g) (CT) and high-fat diet (4.38 kcal per 1 g) (CT/OB, BIX and BIX/ßCD) (n = 10 per group). After 16 weeks, the BIX and BIX/ßCD were treated by gavage (100 µL day-1) for six weeks, with water (CT and CT/OB groups) and (50 mg kg-1 day-1), Bixin (BIX group) or Bix: ß-CD (BIX/ßCD). Body weight, Lee's Index, adiposity, CHT, TG, CHT/HDL-c, glucose levels (metabolic markers) and, liver markers (AST and ALT) were determined. All metabolic and liver parameters exhibited down-regulation after oral administration of BIX and BIX/ßCD. Particularly relevant was Lee's Index and adiposity in BIX- and BIX/ßCD-treated groups (339.18 g/cm -BIX and 327.58 g/cm -BIX/ßCD vs. 360.68 g/cm -CT/OB animals), this finds associated with the insulin sensitivity test, showed a clear association between reduction of adipose tissue and decrease of peripherical insulin resistant. In conclusion, our study suggested that the oral administration of the Bixin and Bix: ß-CD inclusion compound improved the metabolic parameters evaluate in obese mice, being more palatable and hepatoprotective.


Assuntos
Glicemia/efeitos dos fármacos , Carotenoides/farmacologia , Dieta Hiperlipídica , Fígado Gorduroso/prevenção & controle , Transtornos do Metabolismo de Glucose/prevenção & controle , Hipoglicemiantes/farmacologia , Hipolipemiantes/farmacologia , Lipídeos/sangue , Fígado/efeitos dos fármacos , Obesidade/tratamento farmacológico , beta-Ciclodextrinas/farmacologia , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Adipócitos/patologia , Adiposidade/efeitos dos fármacos , Animais , Biomarcadores/sangue , Glicemia/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Fígado Gorduroso/sangue , Fígado Gorduroso/etiologia , Fígado Gorduroso/patologia , Transtornos do Metabolismo de Glucose/sangue , Transtornos do Metabolismo de Glucose/etiologia , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/sangue , Obesidade/etiologia , Obesidade/patologia , Fatores de Tempo
12.
Obesity (Silver Spring) ; 26(3): 531-539, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29377630

RESUMO

OBJECTIVE: Obesity is a highly prevalent multifactorial metabolic condition in which the need for functional bioengineered substitutes (e.g., scaffolds for tissue engineering) is likely to occur. However, the adverse foreign body response (FBR) that invariably takes place adjacent to implant devices impairing their function is poorly characterized in this condition. This study investigated the influence of obesity on the host response to a synthetic matrix implanted subcutaneously in high-fat-fed obese mice. METHODS: Histological analysis of 14-day-old implants was performed to identify collagen deposition, capsule thickness, fibroblast-like cells, foreign body giant cells, and mast cells. In addition, transforming growth factor ß1 (TGF-ß1) levels in the implants and serum were determined. RESULTS: All fibrogenic markers (and TGF-ß1 levels) increased in the implants of obese mice compared with their nonobese counterparts. Particularly relevant was the fibrous capsule thickness in implants of obese mice (234.2 ± 22.1 µm vs. 109.2 ± 13.4 µm in implants of nonobese animals). CONCLUSIONS: The study results showing that obesity upregulates the main features of the FBR induced by subcutaneous implants in mice may be relevant in understanding biomaterial integration and performance in this condition. This is crucial to the development of strategies to maintain the integrity and function of implantable devices.


Assuntos
Corpos Estranhos/complicações , Animais , Reação a Corpo Estranho , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Regulação para Cima
13.
Pancreatology ; 18(2): 221-229, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29289464

RESUMO

BACKGROUND/OBJECTIVES: Pancreas regenerative capacity after injury is not always sufficient to comply with the body's requirement of digestive enzymes and hormones. We present an alternative system to induce pancreas parenchyma proliferation (exocrine and endocrine components), rather than regeneration or remodeling in normoglycemic mice. METHODS: Porous discs of polyether-polyurethane were surgically placed adjacent to the native pancreas and removed at days 15, 30 and 45 after implantation. No exogenous growth factors or extracellular matrix components were added to the platform. The synthetic matrix provided a platform that was filled with parenchymal and non-parenchymal pancreas tissue as detected by histological analysis. Immunohistochemistry analysis were performed to identify insulin positive cells in the newly formed tissue. In addition, angiogenic, inflammatory and metabolic parameters were carried out in those mice. RESULTS: At day 15, the pores of the platform were filled with inflammatory cells, spindled-shaped like fibroblasts, extracellular matrix components, blood vessels and clusters of pancreatic parenchyma (acini, ducts and islet-like structures). At days 30 and 45 the pancreas features remained well organized; its organization resembled that of a native pancreas. Interestingly, besides islet-like structures that showed positive cells to insulin, some ductal cells were also positive for insulin immunostaining. No significant differences in serum glucose and c-peptide concentrations during the experimental period were detected. CONCLUSIONS: The plain synthetic porous platform (without addition of exogenous molecules) placed adjacent to the native organ exhibits potential to restore and/or expand exocrine (acini, ducts) and endocrine (ß-cell mass) components in pancreatic injuries and in high metabolic demand.


Assuntos
Pâncreas/fisiologia , Tecido Parenquimatoso/fisiologia , Engenharia Tecidual , Alicerces Teciduais , Animais , Proliferação de Células , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Polímeros/metabolismo , Poliuretanos
14.
Life Sci ; 193: 226-233, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29097158

RESUMO

AIMS: Currently, animal models of liver regeneration are based on extensive lesions of the native organ and on cellular approaches using biomaterials to host growth factors and extracellular components to create artificial liver systems. We report a polymeric biological platform, minimally invasive, that induced sequential proliferation of liver parenchyma inside the scaffold in mice. MAIN METHODS: Porous discs of polyether-polyurethane were surgically placed under the left liver lobe and removed at days 4, 8, 12 and 25 after implantation. No exogenous growth factors or extracellular matrix components were added to the scaffold. Histological analysis of the implants was performed to identify hepatocytes, liver vascular structures and bile ducts in the newly formed tissue. In addition, systemic markers for hepatic function were determined. KEY FINDINGS: This biohybrid device provided a scaffold that was gradually filled with parenchymal and non-parenchymal liver tissue as detected by histological analysis. At day 4, the pores of the scaffold were filled with inflammatory cells and spindled-shaped like fibroblasts, and extracellular matrix components. At day 8, hepatocytes clusters, central lobular hepatic veins, portal space containing arteries, veins and biliary ducts were detected. By days 12 and 25 a liver-like structure filled 2/3 of the scaffold. Its organization resembled that of a mature liver. Serum concentration of ALT increased three-fold initially after implantation, returning gradually to control levels. SIGNIFICANCE: The plain synthetic scaffold (without addition of exogenous molecules) placed under the intact left liver lobe exhibits the potential to investigate physiological mechanisms that regulate liver parenchyma proliferation.


Assuntos
Proliferação de Células/fisiologia , Regeneração Hepática/fisiologia , Transplante de Fígado/métodos , Animais , Éteres , Matriz Extracelular/química , Matriz Extracelular/fisiologia , Hepatócitos/citologia , Fígado/metabolismo , Camundongos , Tecido Parenquimatoso/fisiologia , Polímeros/metabolismo , Poliuretanos , Alicerces Teciduais
15.
Life Sci ; 176: 67-74, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28336399

RESUMO

AIMS: Several alternative cellular approaches using biomaterials to host insulin-producing cells derived from stem cells have been developed to overcome the limitations of type 1 diabetes treatment (exogenous insulin injection). However, none seem to fulfill all requirements needed to induce pancreatic cells successful colonization of the scaffolds. Here, we report a polymeric platform adherent to the native mice pancreas filled with human adipose stem cells (hASCs) that was able to induce growth of pancreatic parenchyma. MAIN METHODS: Synthetic polyether-polyurethane discs were placed adjacent to pancreas of normoglycemic and streptozotocin-induced diabetic mice. At day 4 post implantation, 1×106 hASCs were injected intra-implant in groups of normoglycemic and diabetic mice. Immunohistochemistry analysis of the implants was performed to identify insulin positive cells in the newly formed tissue. In addition, metabolic, inflammatory and angiogenic parameters were carried out in those mice. KEY FINDINGS: This study provides evidence of the ability of a biohybrid device to induce the growth of differentiated pancreas parenchyma in both normoglycemic and streptozotocin-induced diabetic mice as detected by histological analysis. Glucose metabolism and body weight of hyperglycemic mice bearing hASCs implants improved. SIGNIFICANCE: The synthetic porous scaffold bearing hASC cells placed adjacent to the native animal pancreas exhibits the potential to be exploited in future cell-based type 1 diabetes therapies.


Assuntos
Tecido Adiposo/metabolismo , Diabetes Mellitus Experimental , Matriz Extracelular/química , Células Secretoras de Insulina/metabolismo , Poliuretanos/química , Regeneração , Transplante de Células-Tronco , Células-Tronco/metabolismo , Animais , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/terapia , Xenoenxertos , Humanos , Células Secretoras de Insulina/patologia , Masculino , Camundongos , Células-Tronco/patologia
16.
Biomed Pharmacother ; 86: 715-724, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28063402

RESUMO

Genetic susceptibility is associated with inflammation, neovascularization, and diabetes phenotypes. However, to what extent this susceptibility influences inflammatory angiogenesis in internal injuries in diabetes has not been fully investigated. Using the subcutaneous implantation of a synthetic matrix as an internal wound model in Swiss, C57BL/6 and Balb/c mice, we have studied inflammation, angiogenesis, and cytokine production in the fibrovascular tissue induced by implants in diabetic animals. The hyperglycemic levels (mg/dl) after the diabetogenic treatment were 455.0±15 in Swiss, 393.0±22 in C57BL/6, and 190.0±10 in Balb/c mice. Angiogenesis in Swiss implants from non-diabetic animals were higher than those in the implants from the other strains. However, the angiogenic inducers VEGF and nitric oxide (NO) were higher in implants from non-diabetic Swiss and Balb/c mice. Strain-related differences were also observed in the angiogenic parameters in implants from diabetic mice. Hb content and number of vessels decreased more than 40% in Swiss implants. In contrast, Hb content did not alter in implants from Balb/c diabetic mice and the number of vessels decreased. VEGF levels increased in implants from Swiss and C57BL/6 diabetic mice, but decreased in Balb/c implants. The levels of pro-inflammatory markers intra-implant also varied among the strains in both conditions. In the hyperglycemic environment, almost all inflammatory markers increased in implants from diabetic Swiss mice. These findings demonstrate the major contribution of genetic background in the pattern of inflammatory angiogenesis components of internal injury, in both normoglycemic and hyperglycemic animals.


Assuntos
Diabetes Mellitus Experimental/patologia , Inflamação/patologia , Neovascularização Patológica/patologia , Ferimentos e Lesões/patologia , Animais , Biomarcadores/metabolismo , Diabetes Mellitus Experimental/metabolismo , Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Neovascularização Patológica/metabolismo , Óxido Nítrico/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Cicatrização/fisiologia , Ferimentos e Lesões/metabolismo
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