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1.
Hepatology ; 69(2): 817-830, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30141207

RESUMO

Clinical conditions that result in endotoxemia, such as sepsis and alcoholic hepatitis (AH), often are accompanied by cholestasis. Although hepatocellular changes in response to lipopolysaccharide (LPS) have been well characterized, less is known about whether and how cholangiocytes contribute to this form of cholestasis. We examined effects of endotoxin on expression and function of the type 3 inositol trisphosphate receptor (ITPR3), because this is the main intracellular Ca2+ release channel in cholangiocytes, and loss of it impairs ductular bicarbonate secretion. Bile duct cells expressed the LPS receptor, Toll-like receptor 4 (TLR4), which links to activation of nuclear factor-κB (NF-κB). Analysis of the human ITPR3 promoter revealed five putative response elements to NF-κB, and promoter activity was inhibited by p65/p50. Nested 0.5- and 1.0-kilobase (kb) deletion fragments of the ITPR3 promoter were inhibited by NF-κB subunits. Chromatin immunoprecipitation (ChIP) assay showed that NF-κB interacts with the ITPR3 promoter, with an associated increase in H3K9 methylation. LPS decreased ITPR3 mRNA and protein expression and also decreased sensitivity of bile duct cells to calcium agonist stimuli. This reduction was reversed by inhibition of TLR4. ITPR3 expression was decreased or absent in cholangiocytes from patients with cholestasis of sepsis and from those with severe AH. Conclusion: Stimulation of TLR4 by LPS activates NF-κB to down-regulate ITPR3 expression in human cholangiocytes. This may contribute to the cholestasis that can be observed in conditions such as sepsis or AH.


Assuntos
Ductos Biliares/efeitos dos fármacos , Ductos Biliares/metabolismo , Endotoxemia/metabolismo , Endotoxinas/toxicidade , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Adulto , Sinalização do Cálcio/efeitos dos fármacos , Colestase/etiologia , Colestase/metabolismo , Endotoxemia/complicações , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Hepatite Alcoólica/metabolismo , Humanos , Receptores de Inositol 1,4,5-Trifosfato/genética , Masculino , Pessoa de Meia-Idade , NF-kappa B/metabolismo
2.
Gut ; 68(9): 1676-1687, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31315892

RESUMO

BACKGROUND & OBJECTIVES: Hepatocellular carcinoma (HCC) is the second leading cause of cancer death worldwide. Several types of chronic liver disease predispose to HCC, and several different signalling pathways have been implicated in its pathogenesis, but no common molecular event has been identified. Ca2+ signalling regulates the proliferation of both normal hepatocytes and liver cancer cells, so we investigated the role of intracellular Ca2+ release channels in HCC. DESIGN: Expression analyses of the type 3 isoform of the inositol 1, 4, 5-trisphosphate receptor (ITPR3) in human liver samples, liver cancer cells and mouse liver were combined with an evaluation of DNA methylation profiles of ITPR3 promoter in HCC and characterisation of the effects of ITPR3 expression on cellular proliferation and apoptosis. The effects of de novo ITPR3 expression on hepatocyte calcium signalling and liver growth were evaluated in mice. RESULTS: ITPR3 was absent or expressed in low amounts in hepatocytes from normal liver, but was expressed in HCC specimens from three independent patient cohorts, regardless of the underlying cause of chronic liver disease, and its increased expression level was associated with poorer survival. The ITPR3 gene was heavily methylated in control liver specimens but was demethylated at multiple sites in specimens of patient with HCC. Administration of a demethylating agent in a mouse model resulted in ITPR3 expression in discrete areas of the liver, and Ca2+ signalling was enhanced in these regions. In addition, cell proliferation and liver regeneration were enhanced in the mouse model, and deletion of ITPR3 from human HCC cells enhanced apoptosis. CONCLUSIONS: These results provide evidence that de novo expression of ITPR3 typically occurs in HCC and may play a role in its pathogenesis.


Assuntos
Carcinoma Hepatocelular/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Neoplasias Hepáticas/metabolismo , Adulto , Animais , Apoptose/fisiologia , Sinalização do Cálcio/fisiologia , Carcinogênese/genética , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Proliferação de Células/fisiologia , Células Cultivadas , Metilação de DNA , Feminino , Regulação Neoplásica da Expressão Gênica/fisiologia , Hepatócitos/metabolismo , Humanos , Receptores de Inositol 1,4,5-Trifosfato/deficiência , Receptores de Inositol 1,4,5-Trifosfato/genética , Fígado/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Regeneração Hepática/fisiologia , Masculino , Camundongos Knockout , Pessoa de Meia-Idade , Análise de Sobrevida
3.
Int J Mol Sci ; 20(14)2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31340446

RESUMO

Alcoholic liver disease (ALD) is a highly prevalent spectrum of pathologies caused by alcohol overconsumption. Morbidity and mortality related to ALD are increasing worldwide, thereby demanding strategies for early diagnosis and detection of ALD predisposition. A potential candidate as a marker for ALD susceptibility is the transcription factor nuclear factor erythroid-related factor 2 (Nrf2), codified by the nuclear factor erythroid 2-related factor 2 gene (NFE2L2). Nrf2 regulates expression of proteins that protect against oxidative stress and inflammation caused by alcohol overconsumption. Here, we assessed genetic variants of NFE2L2 for association with ALD. Specimens from patients diagnosed with cirrhosis caused by ALD were genotyped for three NFE2L2 single nucleotide polymorphisms (SNP) (SNPs: rs35652124, rs4893819, and rs6721961). Hematoxylin & eosin and immunohistochemistry were performed to determine the inflammatory score and Nrf2 expression, respectively. SNPs rs4893819 and rs6721961 were not specifically associated with ALD, but analysis of SNP rs35652124 suggested that this polymorphism predisposes to ALD. Furthermore, SNP rs35652124 was associated with a lower level of Nrf2 expression. Moreover, liver samples from ALD patients with this polymorphism displayed more severe inflammatory activity. Together, these findings provide evidence that the SNP rs35652124 variation in the Nrf2-encoding gene NFE2L2 is a potential genetic marker for susceptibility to ALD.


Assuntos
Predisposição Genética para Doença , Cirrose Hepática Alcoólica/genética , Fator 2 Relacionado a NF-E2/genética , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Adulto , Estudos de Casos e Controles , Etanol/farmacologia , Feminino , Expressão Gênica , Hepacivirus/crescimento & desenvolvimento , Hepacivirus/patogenicidade , Hepatite C/patologia , Hepatite C/virologia , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática Alcoólica/metabolismo , Cirrose Hepática Alcoólica/patologia , Cirrose Hepática Alcoólica/cirurgia , Transplante de Fígado , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo
4.
Am J Physiol Gastrointest Liver Physiol ; 315(1): G80-G94, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29471671

RESUMO

Hepatocyte proliferation during liver regeneration is a well-coordinated process regulated by the activation of several growth factor receptors, including the insulin receptor (IR). The IR can be localized in part to cholesterol-enriched membrane microdomains, but the role of such domains in insulin-mediated events in hepatocytes is not known. We investigated whether partitioning of IRs into cholesterol-enriched membrane rafts is important for the mitogenic effects of insulin in the hepatic cells. IR and lipid rafts were labeled in HepG2 cells and primary rat hepatocytes. Membrane cholesterol was depleted in vitro with metyl-ß-cyclodextrin (MßCD) and in vivo with lovastatin. Insulin-induced calcium (Ca2+) signals studies were examined in HepG2 cells and in freshly isolated rat hepatocytes as well as in whole liver in vivo by intravital confocal imaging. Liver regeneration was studied by 70% partial hepatectomy (PH), and hepatocyte proliferation was assessed by PCNA staining. A subpopulation of IR was found in membrane microdomains enriched in cholesterol. Depletion of cholesterol from plasma membrane resulted in redistribution of the IR along the cells, which was associated with impaired insulin-induced nuclear Ca2+ signals, a signaling event that regulates hepatocyte proliferation. Cholesterol depletion also led to ERK1/2 hyper-phosphorylation. Lovastatin administration to rats decreased hepatic cholesterol content, disrupted lipid rafts and decreased insulin-induced Ca2+ signaling in hepatocytes, and delayed liver regeneration after PH. Therefore, membrane cholesterol content and lipid rafts integrity showed to be important for the proliferative effects of insulin in hepatic cells. NEW & NOTEWORTHY One of insulin's actions is to stimulate liver regeneration. Here we show that a subpopulation of insulin receptors is in a specialized cholesterol-enriched region of the cell membrane and this subfraction is important for insulin's proliferative effects.


Assuntos
Cálcio/metabolismo , Colesterol/metabolismo , Hepatócitos/metabolismo , Insulina/metabolismo , Regeneração Hepática/fisiologia , Microdomínios da Membrana/fisiologia , Receptor de Insulina/metabolismo , Animais , Proliferação de Células/fisiologia , Ratos , Transdução de Sinais/fisiologia
5.
Early Hum Dev ; 177-178: 105720, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36773505

RESUMO

AIMS: To describe the General Movements (GMs) of hospitalized newborns to verify if their global and detailed GMA are related and if their GMs are associated with clinical features. METHODS: Cross-sectional study. Thirty-eight preterm and full-term newborns, who were hospitalized in the neonatal intermediate care unit of a reference hospital, were included. Prechtl's General Movement Assessment (GMA), including the General Movement Optimality Score (GMOS) list, was used as an assessment tool. Clinical variables, such as preterm birth, birthweight, length of hospitalization, Apgar scores, pregnancy problems, admission at neonatal intensive care unit, use of invasive mechanical ventilation, and brain imaging findings were also collected. Newborns were videoed at a single time for 3 min before discharge. RESULTS: Most newborns presented GMs with normal or poor repertoire quality. GMOS ranged from 17 to 42 points. Scores were lower in abnormal GMs. Abnormal GMs were associated with preterm birth, length of hospital stay >30 days and birthweight <2500 g. Accordingly, lower GMOSs were also associated with preterm birth, a birthweight <2500 g and a hospital stay >30 days but also with the invasive mechanical ventilation application. CONCLUSION: Preterm and full-term newborns presented normal or abnormal GMs during hospitalization. Preterm birth, low birthweight, longer hospital stay and a time period of invasive ventilation were associated with worse GM behaviors.


Assuntos
Discinesias , Nascimento Prematuro , Feminino , Recém-Nascido , Humanos , Gravidez , Lactente , Recém-Nascido Prematuro , Estudos Transversais , Peso ao Nascer , Movimento , Hospitalização
6.
Front Psychol ; 14: 1278774, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37965660

RESUMO

Introduction: The onset of manual reaching allows the expansion of the infant's interaction with the environment. When born preterm, infants become vulnerable to problems in the development of reaching. However, it is still unknown whether there are differences in reaching according to the degree of prematurity. Objective: This study aimed to explore the differences in reaching acquisition and behavior between late preterm and very preterm infants, as well as whether age and clinical variables influence the results. Method: This is an exploratory, comparative, observational study. In total, 24 infants were included soon after reaching onset; 12 infants were born late preterm (35.55 ± 0.67 gestational weeks) and 12 very preterm (30.60 ± 0.05 gestational weeks). Infants were placed in a baby seat, and a toy was placed at a reachable distance for 2 min. Reaching behavior was the primary variable; birth weight and length of hospital stay were secondary variables. Results: The age of reaching onset was higher in the very preterm group. The proportion of reaches with grasping was higher in the late preterm group. These differences were affected by the lower birth weight and longer length of hospital stay in the very preterm group. The proportions of proximal and distal adjustments did not differ between groups. Conclusion: Very preterm infants presented disadvantages in the acquisition time and the number of reaches with grasping, but not in the proportions of proximal and distal adjustments of reaching, relative to late preterm infants. Group differences were influenced by clinical variables.

7.
Early Hum Dev ; 183: 105822, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37454445

RESUMO

AIM: To characterize the motor repertoire of 3- to 5-month-old infants who were prenatally exposed to the infectious agents of syphilis and toxoplasmosis. METHODS: Exploratory observational study that evaluated 15 exposed infants (34.4 ± 3.5 weeks gestation) recruited from a referral center. Age assessment ranged 12-20 (median 12) weeks post-term. General Movement Assessment, including the Motor Optimality Score-Revised (MOS-R), was used to assess the global quality of fidgety movements (FMs) and to quantify and detail coexisting motor patterns. Clinical variables were also collected. Later motor outcomes were obtained from medical reports when possible. RESULTS: MOS-R ranged 10-26 (median 24). There was a higher proportion of infants with normal (80.0 %) than aberrant FMs, but the proportion of infants with reduced MOS-R (80.0 %) was higher compared to optimal MOS-R. One infant with aberrant FMs was later diagnosed with cerebral palsy. Only 13.3 % of the infants showed smooth and fluent movement character. All observed tongue movements were abnormal. CONCLUSION: Infants had predominantly normal FMs, but with reduced MOS-R and abnormalities in the coexisting motor repertoire.


Assuntos
Paralisia Cerebral , Efeitos Tardios da Exposição Pré-Natal , Sífilis , Toxoplasmose , Gravidez , Feminino , Humanos , Lactente , Movimento , Paralisia Cerebral/diagnóstico
8.
Oncol Lett ; 23(1): 32, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34966448

RESUMO

The expression of the inositol 1,4,5-trisphosphate receptor type 3 (ITRP3) in hepatocytes is a common event in the pathogenesis of hepatocellular carcinoma (HCC), regardless of the type of underlying liver disease. However, it is not known whether ITPR3 expression in hepatocytes is involved in tumor maintenance. The aim of the present study was to determine whether there is an association between ITPR3 expression and clinical and morphological parameters using HCC samples obtained from liver explants from patients (n=53) with different etiologies of underlying chronic liver disease (CLD). ITPR3 expression, mitosis and apoptosis were analyzed in human liver samples by immunohistochemistry. Clinical and event-free survival data were combined to assess the relationship between ITPR3 and liver cancer growth in patients. RNA sequencing analysis was performed to identify apoptotic genes altered by ITPR3 expression in a liver tumor cell line. ITPR3 was highly expressed in HCC tumor cells relative to adjacent CLD tissue and healthy livers. There was an inverse correlation between ITPR3 expression and mitotic and apoptotic indices in HCC, suggesting that ITPR3 contributed to the maintenance of HCC by promoting resistance to apoptosis. This was confirmed by the upregulation of CTSB, CHOP and GADD45, genes involved in the apoptotic pathway in HCC. The expression of ITPR3 in the liver may be a promising prognostic marker of HCC.

9.
Chem Biol Interact ; 351: 109734, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34742685

RESUMO

Malignant melanoma has a low incidence, but is the most lethal type of skin cancer. Studies have shown that dibenzoylmethanes (DBMs) have interesting biological activities, including antineoplastic properties. These findings led us to investigate whether news DBM derivatives exert antitumor effects against skin cancers. In a previous study, we found that 1,3-diphenyl-2-benzyl-1,3-propanedione (DPBP) has high in vitro antineoplastic activity against murine B16F10 melanoma cells, with an IC50 of 6.25 µg/mL. In the current study, we used transdermal and topical formulations of DPBP to evaluate its activity and molecular mechanism of action in a murine model of melanoma. The compound induces tumor cell death with high selectivity (selectivity index of 41.94) by triggering apoptosis through intrinsic and extrinsic pathways. DPBP treatment reduced tumor volume as well as serum VEGF-A and uric acid levels. Hepatomegaly and nephrotoxicity were not observed at the tested doses. Histopathological analysis of sentinel lymph nodes revealed no evidence of metastases. According to the observed data, the DPBP compound was effective for the topical treatment of melanoma cancer, suggesting that it acts as a chemotherapeutic or chemopreventive agent.


Assuntos
Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Chalconas/uso terapêutico , Melanoma Experimental/tratamento farmacológico , Animais , Antineoplásicos/síntese química , Linhagem Celular Tumoral , Chalconas/síntese química , Masculino , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos
10.
PLoS One ; 16(7): e0250394, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34237060

RESUMO

Plant species from Annonaceae are commonly used in traditional medicine to treat various cancer types. This study aimed to investigate the antiproliferative potential of an alkaloid and acetogenin-rich fraction from the fruit peel of Annona crassiflora in HepG2 cells. A liquid-liquid fractionation was carried out on the ethanol extract of A. crassiflora fruit peel in order to obtain an alkaloid and acetogenin-rich fraction (AF-Ac). Cytotoxicity, proliferation and migration were evaluated in the HepG2 cells, as well as the proliferating cell nuclear antigen (PCNA), vinculin and epidermal growth factor receptor (EGFR) expression. In addition, intracellular Ca2+ was determined using Fluo4-AM and fluorescence microscopy. First, 9 aporphine alkaloids and 4 acetogenins that had not yet been identified in the fruit peel of A. crassiflora were found in AF-Ac. The treatment with 50 µg/mL AF-Ac reduced HepG2 cell viability, proliferation and migration (p < 0.001), which is in accordance with the reduced expression of PCNA and EGFR levels (p < 0.05). Furthermore, AF-Ac increased intracellular Ca2+ in the HepG2 cells, mobilizing intracellular calcium stores, which might be involved in the anti-migration and anti-proliferation capacities of AF-Ac. Our results support the growth-inhibitory potential of AF-Ac on HepG2 cells and suggest that this effect is triggered, at least in part, by PCNA and EGFR modulation and mobilization of intracellular Ca2+. This study showed biological activities not yet described for A. crassiflora fruit peel, which provide new possibilities for further in vivo studies to assess the antitumoral potential of A. crassiflora, especially its fruit peel.


Assuntos
Acetogeninas/análise , Alcaloides/análise , Annona/química , Frutas/química , Neoplasias Hepáticas/patologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Hep G2 , Humanos
11.
Cell Calcium ; 91: 102264, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32957029

RESUMO

Hepatic ischemia-reperfusion injury is seen in a variety of clinical conditions, including hepatic thrombosis, systemic hypotension, and liver transplantation. Calcium (Ca2+) signaling mediates several pathophysiological processes in the liver, but it is not known whether and how intracellular Ca2+ channels are involved in the hepatocellular events secondary to ischemia-reperfusion. Using an animal model of hepatic ischemia-reperfusion injury, we observed a progressive increase in expression of the type 3 isoform of the inositol trisphosphate receptor (ITPR3), an intracellular Ca2+ channel that is not normally expressed in healthy hepatocytes. ITPR3 expression was upregulated, at least in part, by a combination of demethylation of the ITPR3 promoter region and the increased transcriptional activity of the nuclear factor of activated T-cells (NFAT). Additionally, expression of pro-inflammatory interleukins and necrotic surface area were less pronounced in livers of control animals compared to liver-specific ITPR3 KO mice subjected to hepatic damage. Corroborating these findings, ITPR3 expression and activation of NFAT were observed in hepatocytes of liver biopsies from patients who underwent liver ischemia caused by thrombosis after organ transplant. Together, these results are consistent with the idea that ITPR3 expression in hepatocytes plays a protective role during hepatic injury induced by ischemia-reperfusion.


Assuntos
Hepatócitos/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Fígado/metabolismo , Fígado/patologia , Substâncias Protetoras/metabolismo , Traumatismo por Reperfusão/metabolismo , Animais , Sinalização do Cálcio , Desmetilação do DNA , Modelos Animais de Doenças , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fatores de Transcrição NFATC/metabolismo , Regiões Promotoras Genéticas/genética
12.
Hepatol Commun ; 4(5): 657-669, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32363317

RESUMO

Yellow fever (YF) is a viral hemorrhagic fever that typically involves the liver. Brazil recently experienced its largest recorded YF outbreak, and the disease was fatal in more than a third of affected individuals, mostly because of acute liver failure. Affected individuals are generally treated only supportively, but during the recent Brazilian outbreak, selected patients were treated with liver transplant. We took advantage of this clinical experience to better characterize the clinical and pathological features of YF-induced liver failure and to examine the mechanism of hepatocellular injury in YF, to identify targets that would be amenable to therapeutic intervention in preventing progression to liver failure and death. Patients with YF liver failure rapidly developed massive transaminase elevations, with jaundice, coagulopathy, thrombocytopenia, and usually hepatic encephalopathy, along with pathological findings that included microvesicular steatosis and lytic necrosis. Hepatocytes began to express the type 3 isoform of the inositol trisphosphate receptor (ITPR3), an intracellular calcium (Ca2+) channel that is not normally expressed in hepatocytes. Experiments in an animal model, isolated hepatocytes, and liver-derived cell lines showed that this new expression of ITPR3 was associated with increased nuclear Ca2+ signaling and hepatocyte proliferation, and reduced steatosis and cell death induced by the YF virus. Conclusion: Yellow fever often induces liver failure characterized by massive hepatocellular damage plus steatosis. New expression of ITPR3 also occurs in YF-infected hepatocytes, which may represent an endogenous protective mechanism that could suggest approaches to treat affected individuals before they progress to liver failure, thereby decreasing the mortality of this disease in a way that does not rely on the costly and limited resource of liver transplantation.

13.
Musculoskelet Sci Pract ; 42: 84-89, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31054486

RESUMO

Non-specific low back pain is a common complaint frequently presented by patients and this complex clinical condition has challenged the biomedical model. The Biopsychosocial (BPS) model is recognized as an option for better guidance and patient management. However, physiotherapy training is based on the biomedical perspective, added to which, in clinical practice the applicability of the BPS model is a challenge for many professionals. In this article, we explore the feelings, beliefs, and attitudes of newly trained physiotherapists about using the BPS model to treat people with non-specific low back pain. It also aims to understand to what extent these physiotherapists are willing and prepared to use this model. Method: A qualitative phenomenological research was carried out in the Brazilian federal capital. A set of criteria was used to select 10 physiotherapists. The data were collected through semi-structured interviews and analyzed using five steps: familiarization, identification, indexation, mapping, and interpretation. Results: We identified one theme and three categories. The theme 'a practitioner physiotherapist can consider BPS aspects, but it is not necessary in his/her role to approach them' explains a shared belief about the use of BPS. The theme is better understood when looking at the three categories that explore and exemplify key elements of the theme: (i) understanding the BPS model and its relation to non-specific low back pain; (ii) the role of practitioner physiotherapists regarding the BPS model; and (iii) barriers: from undergraduate training to clinical settings.


Assuntos
Atitude do Pessoal de Saúde , Dor Lombar/terapia , Fisioterapeutas/psicologia , Adulto , Brasil , Feminino , Humanos , Entrevistas como Assunto , Masculino , Modalidades de Fisioterapia
14.
Int J Biol Macromol ; 132: 811-821, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30946907

RESUMO

The present work describes in vitro and in vivo behaviors of thermosensitive composite hydrogels based on polymers/bioactive glass nanoparticles. Assays in SBF (simulated body fluid) solution showed that loss of hydrogel mass in vitro was decreased by 4.3% when bioactive glass nanoparticles (nBG) were incorporated, and confirmed the bioactivity of nBG containing hydrogels. In vitro assays demonstrated the cytocompatibility of the hydrogels with encapsulated rat bone marrow mesenchymal stem cells (BMSC). Crystal violet assays showed a 27% increase in cell viability when these cells were seeded in hydrogels containing nBG. In vivo biocompatibility was examined by injecting hydrogels into the dorsum of Swiss rats. The results indicated that the prepared hydrogels were nontoxic upon subcutaneous injection, and could be candidates for a safe in situ gel-forming system. Injection of the hydrogels into a rat tibial defect allowed preliminary evaluation of the hydrogels' regenerative potential. Micro Computed Tomography analysis suggested that more new tissue was formed in the defects treated with the hydrogels. Taken together, our data suggest that the developed injectable composite hydrogels possess properties which make them suitable candidates for use as temporary injectable matrices for bone regeneration.


Assuntos
Materiais Biocompatíveis/farmacologia , Regeneração Óssea/efeitos dos fármacos , Quitosana/química , Gelatina/química , Vidro/química , Hidrogéis/química , Nanocompostos/química , Animais , Materiais Biocompatíveis/administração & dosagem , Materiais Biocompatíveis/química , Sobrevivência Celular/efeitos dos fármacos , Feminino , Injeções , Teste de Materiais , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Ratos , Ratos Wistar , Tíbia/citologia , Tíbia/diagnóstico por imagem , Tíbia/efeitos dos fármacos , Tíbia/fisiologia , Engenharia Tecidual , Alicerces Teciduais/química , Microtomografia por Raio-X
15.
Biophys Chem ; 239: 1-6, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29753256

RESUMO

Melanoma accounts for only 4% of all skin cancers but is among the most lethal cutaneous neoplasms. Dacarbazine is the drug of choice for the treatment of melanoma in Brazil through the public health system mainly because of its low cost. However, it is an alkylating agent of low specificity and elicits a therapeutic response in only 20% of cases. Other drugs available for the treatment of melanoma are expensive, and tumor cells commonly develop resistance to these drugs. The fight against melanoma demands novel, more specific drugs that are effective in killing drug-resistant tumor cells. Dibenzoylmethane (1,3-diphenylpropane-1,3-dione) derivatives are promising antitumor agents. In this study, we investigated the cytotoxic effect of 1,3-diphenyl-2-benzyl-1,3-propanedione (DPBP) on B16F10 melanoma cells as well as its direct interaction with the DNA molecule using optical tweezers. DPBP showed promising results against tumor cells and had a selectivity index of 41.94. Also, we demonstrated the ability of DPBP to interact directly with the DNA molecule. The fact that DPBP can interact with DNA in vitro allows us to hypothesize that such an interaction may also occur in vivo and, therefore, that DPBP may be an alternative to treat patients with drug-resistant melanomas. These findings can guide the development of new and more effective drugs.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Chalconas/química , Chalconas/farmacologia , DNA de Neoplasias/química , DNA de Neoplasias/efeitos dos fármacos , Animais , Antineoplásicos/síntese química , Proliferação de Células/efeitos dos fármacos , Chalconas/síntese química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Camundongos , Estrutura Molecular , Pinças Ópticas , Relação Estrutura-Atividade , Células Tumorais Cultivadas
16.
PLoS One ; 12(4): e0175041, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28376104

RESUMO

Increases in nuclear calcium concentration generate specific biological outcomes that differ from those resulting from increased cytoplasmic calcium. Nuclear calcium effects on tumor cell proliferation are widely appreciated; nevertheless, its involvement in other steps of tumor progression is not well understood. Therefore, we evaluated whether nuclear calcium is essential in other additional stages of tumor progression, including key steps associated with the formation of the primary tumor or with the metastatic cascade. We found that nuclear calcium buffering impaired 4T1 triple negative breast cancer growth not just by decreasing tumor cell proliferation, but also by enhancing tumor necrosis. Moreover, nuclear calcium regulates tumor angiogenesis through a mechanism that involves the upregulation of the anti-angiogenic C-X-C motif chemokine 10 (CXCL10-IP10). In addition, nuclear calcium buffering regulates breast tumor cell motility, culminating in less cell invasion, likely due to enhanced vinculin expression, a focal adhesion structural protein. Together, our results show that nuclear calcium is essential for triple breast cancer angiogenesis and cell migration and can be considered as a promising strategic target for triple negative breast cancer therapy.


Assuntos
Sinalização do Cálcio , Inositol 1,4,5-Trifosfato/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular , Núcleo Celular/metabolismo , Proliferação de Células , Quimiocina CXCL10/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Neovascularização Patológica/genética , Neoplasias de Mama Triplo Negativas/irrigação sanguínea , Neoplasias de Mama Triplo Negativas/patologia
17.
PLoS One ; 11(12): e0165371, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27992423

RESUMO

BACKGROUND: The angiotensin-I converting enzyme (ACE) plays a central role in the renin-angiotensin system, acting by converting the hormone angiotensin-I to the active peptide angiotensin-II (Ang-II). More recently, ACE was shown to act as a receptor for Ang-II, and its expression level was demonstrated to be higher in melanoma cells compared to their normal counterparts. However, the function that ACE plays as an Ang-II receptor in melanoma cells has not been defined yet. AIM: Therefore, our aim was to examine the role of ACE in tumor cell proliferation and migration. RESULTS: We found that upon binding to ACE, Ang-II internalizes with a faster onset compared to the binding of Ang-II to its classical AT1 receptor. We also found that the complex Ang-II/ACE translocates to the nucleus, through a clathrin-mediated process, triggering a transient nuclear Ca2+ signal. In silico studies revealed a possible interaction site between ACE and phospholipase C (PLC), and experimental results in CHO cells, demonstrated that the ß3 isoform of PLC is the one involved in the Ca2+ signals induced by Ang-II/ACE interaction. Further studies in melanoma cells (TM-5) showed that Ang-II induced cell proliferation through ACE activation, an event that could be inhibited either by ACE inhibitor (Lisinopril) or by the silencing of ACE. In addition, we found that stimulation of ACE by Ang-II caused the melanoma cells to migrate, at least in part due to decreased vinculin expression, a focal adhesion structural protein. CONCLUSION: ACE activation regulates melanoma cell proliferation and migration.


Assuntos
Angiotensina II/metabolismo , Núcleo Celular/metabolismo , Melanoma/enzimologia , Peptidil Dipeptidase A/metabolismo , Fosfolipase C beta/metabolismo , Vinculina/metabolismo , Animais , Células CHO , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Simulação por Computador , Cricetulus , Humanos , Lisinopril/farmacologia , Melanoma/genética , Melanoma/metabolismo , Peptidil Dipeptidase A/genética , Transporte Proteico
18.
Dent. press implantol ; 9(3): 101-106, July-Sept.2015. ilus, tab
Artigo em Português | LILACS | ID: lil-796649

RESUMO

A osteonecrose dos maxilares associada ao uso de bisfosfonatos tem sido um assunto de muita relevância na clínica odontológica neste século. A alta taxa de utilização desses medicamentos obrigou os cirurgiões-dentistas a buscar conhecimento sobre o tema, uma vez que as lesões necróticas associadas ao uso desses bisfosfonatos afetam negativamente a qualidade de vida e produzem significativa morbidade nos pacientes acometidos. Assim, conhecer a doença, sua epidemiologia, taxa de risco e gerenciamento dos pacientes se faz necessário. Objetivo: o presente trabalho teve como objetivo geral buscar na literatura informações relevantes acerca dessa patologia e desses medicamentos, por meio de uma revisão de literatura. Métodos: levantamento de artigos nas bases de dados EBSCO e MEDLINE, publicados no período de 1996 a 2014. Foram selecionados artigos originais e de revisão que embasaram o desenvolvimento dos tópicos propostos. Resultados: 22 artigos preencheram os critérios estabelecidos. Durante o desenvolvimento da pesquisa, foram encontrados outros medicamentos associados à enfermidade, que também estão sendo relatados nessa revisão. Conclusões: devido à utilização dos bisfosfonatos, o tecido ósseo diminui sua capacidade de reabsorção e, assim, aumenta a possibilidade de não cicatrização e consequente necrose; ainda, fica clara a ação desses medicamentos inibindo a proliferação de células dos tecidos moles e vasos sanguíneos. Por último, evidencia-se que o correto gerenciamento dos pacientes em uso dos fármacos é de grande importância para a submissão desses pacientes a procedimentos cirúrgicos...


Osteonecrosis of the jaw associated with the use of bisphosphonates has been a relevant subject in Dentistry in the last century. The excessive use of these medications obligated dentists to seek knowledge on the theme, since necrotic lesions associated with the use of bisphosphonates affect quality of life negatively, in addition to causing significant morbidity. Thus, being aware of the disease, its epidemiology, risk rate and patient management is necessary. The present study aimed to search literature on relevant information regarding the referred pathology and medications by means of a review. Methods: EBSCO and MEDLINE databases were used, seeking articles published between 1996 and 2014. Original and review articles were selected to base the development of proposed topics. Results: A total of 22 articles fulfilled the established criteria. During the development of the study, other medications associated with the pathology were found and are also reported in this review. Conclusions: Due to the use of bisphosphonates, bone tissue diminishes its resorption capacity and, thus, increases the probability of non-healing and consequent necrosis. In additionthe effects of these medications, inhibiting soft tissue cells and blood vessels proliferation, are clear. At last, it is clear that the correct management of patients using such drugs is of great importance to their submission to surgical procedures...


Assuntos
Humanos , Masculino , Feminino , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos , Difosfonatos/efeitos adversos , Maxila/patologia , Osteoclastos
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