Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Metallomics ; 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31650140

RESUMO

Cadmium (Cd) is a persistent environmental contaminant and induces neurotoxicity in animals. Trehalose (Tre) exhibits powerful neuroprotective effects in certain brain injury models. Herein, we revealed the specific molecular mechanism underlying the protective effects of Tre against Cd-induced brain damage in rats. Firstly, the results showed that Tre significantly ameliorated brain pathological injury induced by Cd. Secondly, Cd-induced down-regulation of total anti-oxidation capacity (T-AOC) and up-regulation of methane dicarboxylic aldehyde (MDA) in brain tissues were significantly reversed by Tre treatment. Importantly, the augmentation of nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) caused by Cd was significantly inhibited by Tre treatment. Thirdly, the levels of autophagy marker proteins were measured and the results showed that Tre significantly reversed the up-regulation of light chain 3II (LC-3II) and sequestosome 1 (SQSTM-1/p62) caused by Cd exposure. Finally, the apoptosis rate and the levels of apoptosis marker proteins including B cell leukemia/lymphoma 2 (Bcl2) and Bcl2-associated X protein (Bax) were also measured and the results showed that Cd-induced apoptosis was markedly inhibited by Tre treatment. Collectively, our data suggested that Tre exerted its neuroprotective effects by ameliorating oxidative stress, autophagy inhibition, and apoptosis induced by Cd in rat brains. In addition, the Nrf2 signaling pathway, which is continuously activated by Cd, may contribute to brain injury.

2.
Ecotoxicol Environ Saf ; 181: 224-230, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31195231

RESUMO

Cadmium (Cd), as a kind of ubiquitous and highly toxic heavy metal pollutants, has been known to result in immunotoxicity in animals. As a multifunctional bioactivity disaccharide, trehalose (Tre) is characterized by antioxidative, antiapoptotic, and accelerating autophagy. In this study, Sprague-Dawley (SD) rats were fed with cadmium chloride (CdCl2) and/or Tre to explore the molecular mechanisms of Tre-protected against spleen injury caused by Cd exposure. Firstly, the results showed that Tre partially recovered splenic pathological changes induced by Cd exposure. Secondly, Tre dramatically declined the level of methane dicarboxylic aldehyde (MDA) and elevated the level of total antioxidant capacity (T-AOC) to weaken oxidative stress caused by Cd exposure in spleen tissue. Moreover, the results showed that Tre significantly suppressed Cd-induced the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and up-regulated the protein expression of nuclear Nrf2. Thirdly, Tre remarkably reduced the protein expression of sequestosome 1 (p62/SQSTM1) and microtubule-associated protein light chain 3II (LC-3II) to restore autophagy inhibition induced by Cd exposure. Finally, the results of TUNEL and the expression of apoptosis marker proteins showed that Tre significantly inhibited Cd-induced apoptosis in spleen tissue to exert its protective effects. In summary, the results indicated that Tre modulated Nrf2 signaling pathway, which interacted with apoptosis and autophagy to against Cd-induced spleen injury, providing potential therapeutic strategies for the prevention and treatment of Cd-related immune system diseases.


Assuntos
Cloreto de Cádmio/toxicidade , Poluentes Ambientais/toxicidade , Fator 2 Relacionado a NF-E2/antagonistas & inibidores , Baço/efeitos dos fármacos , Trealose/farmacologia , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Masculino , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Baço/metabolismo , Baço/patologia
3.
Biol Trace Elem Res ; 2019 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-30805876

RESUMO

Cadmium (Cd), as one of the most toxic heavy metals, has become a widespread environmental contaminant and threats the food quality and safety. The protective effect of selenium (Se) on Cd-induced tissue lesion and cytotoxicity in chicken has been extensively reported. The objective of this study was to investigate the antagonistic effect of Se on Cd-induced damage of chicken pectoral muscles via analyzing the trace elements and amino acids profiles. Firstly, 19 trace elements contents were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that under Cd exposure, the contents of Cd, lead (Pb), mercury (Hg), aluminum (Al), and lithium (Li) were significantly elevated, and the contents of Se, iron (Fe), and chromium (Cr) were significantly reduced. However, supplementing Se significantly reversed the effects induced by Cd. Secondly, the amino acids contents were detected by L-8900 automatic amino acid analyzer. The results showed that supplementing Se increased significantly Cd-induced decrease of valine (Val), leucine (Leu), arginine (Arg), and proline (Pro). Thirdly, the results of principal component analysis (PCA) showed that cobalt (Co), manganese (Mn), silicium (Si), and Pro may play special roles in response to the process of Se antagonizes Cd-induced damage of pectoral muscles in chickens. In summary, these results indicated that different trace elements and amino acids possessed and exhibited distinct responses to suffer from Se and/or Cd in chicken pectoral muscles. Notably, Se alleviated Cd-induced adverse effects by regulating trace elements and amino acids profiles in chicken pectoral muscles.

4.
Biochim Biophys Acta Mol Cell Res ; 1866(4): 713-726, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30528975

RESUMO

Lead (Pb) is a known nephrotoxicant that causes damage to proximal tubular cells. PERK pathway plays an important role in the pathogenesis of renal diseases, but its role in Pb-induced nephrotoxicity remains largely unknown. In this study, data showed that Pb could induce ER stress as shown by increased phosphorylation of PERK with subsequent activation of the eIF2α-ATF4-CHOP axis in primary rat proximal tubular (rPT) cells, indicating the activation of PERK-eIF2α-ATF4-CHOP pathway due to excessive ER stress. Pb-activated PERK pathway can be effectively inhibited by 4-phenylbutyric acid and PERK gene silencing, respectively; whereas continuously up-regulated by tunicamycin (TM) treatment. Moreover, Pb-induced apoptosis and inhibition of autophagic flux in rPT cells were significantly augmented and aggravated by co-treatment with TM, respectively. Pharmacological or genetic inhibition of the PERK pathway results in alleviation of apoptosis and restoration of autophagy inhibition in Pb-exposed rPT cells. Mechanistically, activation of PERK-eIF2α-ATF4-CHOP axis triggered by excessive ER stress in rPT cells leads to Pb-induced apoptosis and blockage of autophagic flux, resulting in nephrotoxicity.


Assuntos
Estresse do Retículo Endoplasmático , Túbulos Renais Proximais/efeitos dos fármacos , Chumbo/toxicidade , eIF-2 Quinase/metabolismo , Fator 4 Ativador da Transcrição/metabolismo , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Células Cultivadas , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Fator de Iniciação 2 em Eucariotos/metabolismo , Túbulos Renais Proximais/enzimologia , Túbulos Renais Proximais/metabolismo , Fenilbutiratos/farmacologia , Ratos Sprague-Dawley , Fator de Transcrição CHOP/metabolismo , Tunicamicina/farmacologia , eIF-2 Quinase/genética
5.
J Inorg Biochem ; 182: 184-193, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29501979

RESUMO

Autophagy and apoptosis are two different biological processes that determine cell fates. We previously reported that autophagy inhibition and apoptosis induction are involved in lead(II)-induced cytotoxicity in primary rat proximal tubular (rPT) cells, but the interplay between them remains to be elucidated. Firstly, data showed that lead(II)-induced elevation of LC3-II protein levels can be significantly modulated by 3-methyladenine or rapamycin; moreover, protein levels of Autophagy-related protein 5 (Atg5) and Beclin-1 were markedly up-regulated by lead(II) treatment, demonstrating that lead(II) could promote the autophagosomes formation in rPT cells. Next, we applied three pharmacological agents and genetic method targeting the early stage of autophagy to validate that enhancement of autophagosomes formation can inhibit lead(II)-induced apoptotic cell death in rPT cells. Simultaneously, lead(II) inhibited the autophagic degradation of rPT cells, while the addition of autophagic degradation inhibitor bafilomycin A1 aggravated lead(II)-induced apoptotic death in rPT cells. Collectively, this study provided us a good model to know about the dynamic process of lead(II)-induced autophagy in rPT cells, and the interplay between autophagy and apoptosis highlights a new sight into the mechanism of lead(II)-induced nephrotoxicity.

6.
J Biochem Mol Toxicol ; 32(1)2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29140578

RESUMO

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that regulates a cluster of oxidative stress-inducible genes in cells. Here, we aimed to investigate whether trehalose (Tre) protects primary rat proximal tubular (rPT) cells against cadmium (Cd)-induced oxidative stress via Nrf2 antioxidant pathway. Data showed that Tre treatment inhibited Nrf2 nuclear translocation and restored the decline in Kelch-like ECH-associated protein 1 (Keap1) protein level in Cd-exposed rPT cells. Moreover, Cd-activated Nrf2 target genes, including phase II detoxifying enzymes, that is, NAD(P)H quinone oxidoreductase 1 and heme oxygenase-1, direct antioxidant proteins, that is, glutathione peroxidase, superoxide dismutase, catalase, and glutathione biosynthesis-related proteins, that is, glutamatecysteine ligase catalytic subunit, glutamate cysteine ligase modifier subunit, and glutathione reductase, were all downregulated by co-treatment with Tre. Collectively, these findings demonstrate that Tre treatment alleviates Cd-induced oxidative stress in rPT cells by inhibiting the Nrf2-Keap1 signaling pathway.


Assuntos
Cádmio/toxicidade , Proteína 1 Associada a ECH Semelhante a Kelch/antagonistas & inibidores , Túbulos Renais Proximais/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/antagonistas & inibidores , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Trealose/metabolismo , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Animais , Cádmio/química , Intoxicação por Cádmio/dietoterapia , Intoxicação por Cádmio/metabolismo , Intoxicação por Cádmio/patologia , Intoxicação por Cádmio/prevenção & controle , Catalase/antagonistas & inibidores , Catalase/química , Catalase/metabolismo , Células Cultivadas , Suplementos Nutricionais , Regulação para Baixo , Glutationa Redutase/antagonistas & inibidores , Glutationa Redutase/química , Glutationa Redutase/metabolismo , Heme Oxigenase-1/antagonistas & inibidores , Heme Oxigenase-1/química , Heme Oxigenase-1/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/agonistas , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Túbulos Renais Proximais/citologia , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , NAD(P)H Desidrogenase (Quinona)/antagonistas & inibidores , NAD(P)H Desidrogenase (Quinona)/química , NAD(P)H Desidrogenase (Quinona)/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Substâncias Protetoras/metabolismo , Substâncias Protetoras/uso terapêutico , Ratos , Superóxido Dismutase/antagonistas & inibidores , Superóxido Dismutase/química , Superóxido Dismutase/metabolismo , Trealose/uso terapêutico
7.
Oncotarget ; 8(53): 91162-91173, 2017 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-29207633

RESUMO

Lead (Pb) is a known nephrotoxic element. Recently we have proved that subcellular Ca2+ redistribution is involved in Pb-induced apoptosis in primary cultures of rat proximal tubular (rPT) cells, but the underlying mechanism remains to be elucidated. Firstly, data showed that Pb triggers endoplasmic reticulum (ER) stress response in rPT cells, as evidenced by the elevations of ER stress markers. Moreover, pharmacological modulation of Ca2+ mobilization in ER and cytoplasm with three chemicals (2-APB or TG or BAPTA-AM) can effectively increase or decrease the protein expression of ER stress markers in Pb-exposed rPT cells, demonstrating that Pb-induced ER stress is Ca2+-dependent. We found that Pb stimulates phosphorylation of calcium/calmodulin-dependent protein kinase II (CaMKII) to activate its activity. Meanwhile, inhibition of CaMKII with KN93 or KN62 attenuated Pb-activated caspase-12 and CCAAT/enhancer-binding protein homologous protein (CHOP) in rPT cells, demonstrating that CaMKII activation promoted ER stress in rPT cells. Likewise, Pb-induced apoptosis can be effectively inhibited by CaMKII inhibitor KN93 or KN62. Furthermore, co-treatment with KN93 or KN62 significantly reversed Pb-induced ER Ca2+ release and concomitant intracellular Ca2+ overload in rPT cells. In summary, these results expound the mechanisms involving in ER stress, Ca2+ dyshomeostasis and activated CaMKII, which all contribute to Pb-induced apoptosis. CaMKII acts as a critical mediator of ER stress and associated apoptosis via regulating intracellular Ca2+ mobilization from ER to cytoplasm.

8.
Cell Death Dis ; 8(10): e3099, 2017 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-29022917

RESUMO

Autophagy has an important renoprotective function and we recently found that autophagy inhibition is involved in cadmium (Cd)-induced nephrotoxicity. Here, we aimed to investigate the protective effect of trehalose (Tre), a novel autophagy activator, against Cd-induced cytotoxicity in primary rat proximal tubular (rPT) cells. First, data showed that Tre treatment significantly decreased Cd-induced apoptotic cell death of rPT cells via inhibiting caspase-dependent apoptotic pathway, evidenced by morphological analysis, flow cytometric and immunoblot assays. Also, administration with Tre protected rPT cells against Cd-induced lipid peroxidation. Inhibition of autophagic flux in Cd-exposed rPT cells was markedly restored by Tre administration, demonstrated by immunoblot analysis of autophagy marker proteins and GFP and RFP tandemly tagged LC3 method. Resultantly, Cd-induced autophagosome accumulation was obviously alleviated by Tre treatment. Meanwhile, blockage of autophagosome-lysosome fusion by Cd exposure was noticeably restored by Tre, which promoted the autophagic degradation in Cd-exposed rPT cells. Moreover, Tre treatment markedly recovered Cd-induced lysosomal alkalinization and impairment of lysosomal degradation capacity in rPT cells, demonstrating that Tre has the ability to restore Cd-impaired lysosomal function. Collectively, these findings demonstrate that Tre treatment alleviates Cd-induced cytotoxicity in rPT cells by inhibiting apoptosis and restoring autophagic flux.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Cádmio/toxicidade , Túbulos Renais Proximais/patologia , Substâncias Protetoras/farmacologia , Trealose/farmacologia , Animais , Autofagossomos/fisiologia , Caspase 3/metabolismo , Caspase 9/metabolismo , Células Cultivadas , Túbulos Renais Proximais/citologia , Túbulos Renais Proximais/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Lisossomos/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Poli(ADP-Ribose) Polimerases/metabolismo , Cultura Primária de Células , Ratos , Ratos Sprague-Dawley
9.
Cell Death Dis ; 8(6): e2863, 2017 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-28594408

RESUMO

Lead (Pb) is a known nephrotoxicant that causes damage to proximal tubular cells. Autophagy has an important protective role in various renal injuries, but the role of autophagy in Pb-elicited nephrotoxicity remains largely unknown. In this study, Pb promoted the accumulation of autophagosomes in primary rat proximal tubular (rPT) cells, and subsequent findings revealed that this autophagosome accumulation was caused by the inhibition of autophagic flux. Moreover, Pb exposure did not affect the autophagosome-lysosome fusion in rPT cells. Next, we found that Pb caused lysosomal alkalinization, may be through suppression of two V-ATPase subunits. Simultaneously, Pb inhibited lysosomal degradation capacity by affecting the maturation of cathepsin B (CTSB) and cathepsin D (CTSD). Furthermore, translocation of CTSB and CTSD from lysosome to cytoplasm was observed in this study, suggesting that lysosomal membrane permeabilization (LMP) occurred in Pb-exposed rPT cells. Meanwhile, Pb-induced caspase-3 activation and apoptosis were significantly but not completely inhibited by CTSB inhibitor (CA 074) and CTSD inhibitor (pepstatin A), respectively, demonstrating that LMP-induced lysosomal enzyme release was involved in Pb-induced apoptosis in rPT cells. In conclusion, Pb-mediated autophagy blockade in rPT cells is attributed to the impairment of lysosomal function. Both inhibition of autophagic flux and LMP-mediated apoptosis contribute to Pb-induced nephrotoxicity in rPT cells.


Assuntos
Autofagia/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Nefropatias , Túbulos Renais Proximais , Chumbo/toxicidade , Lisossomos , Animais , Células Cultivadas , Nefropatias/induzido quimicamente , Nefropatias/metabolismo , Nefropatias/patologia , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Lisossomos/metabolismo , Lisossomos/patologia , Ratos , Ratos Sprague-Dawley
10.
Toxicology ; 383: 13-23, 2017 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-28347754

RESUMO

Previous studies have shown that subcellular Ca2+ redistribution is involved in Cd-induced autophagy inhibition in primary rat proximal tubular (rPT) cells, but the mechanism remains unclear. In this study, the status of autophagic flux was monitored by the GFP and RFP tandemly tagged LC3 method. Pharmacological inhibition of cytosolic Ca2+ concentration ([Ca2+]c) with 2-APB or BAPTA-AM significantly alleviated Cd-elevated yellow puncta formation and restored Cd-inhibited red puncta formation, while thapsigargin (TG) had the opposite regulatory effect, demonstrating that Cd-induced [Ca2+]c elevation inhibited the autophagic flux in rPT cells. Resultantly, Cd-induced autophagosomes accumulation was obviously modulated by 2-APB, BAPTA-AM and TG, respectively. Meanwhile, blockage of autophagosome-lysosome fusion and decreased recruitment of Rab7 to autophagosomes by Cd exposure was noticeably restored by 2-APB or BAPTA-AM, but co-treatment with Cd and TG further impaired Cd-induced autophagy arrest. Moreover, Cd-induced oxidative stress intimately correlated with cytosolic Ca2+ mobilization, and N-acetylcysteine (NAC) markedly rescued Cd-blocked autophagosome-lysosome fusion and recruitment of Rab7 to autophagosomes in rPT cells, implying that Cd-induced autophagy inhibition was due to [Ca2+]c elevation-triggered oxidative stress. In summary, these results suggest that Cd-mediated autophagy inhibition in rPT cells is dependent on cytosolic Ca2+ overload. Elevation of [Ca2+]c inhibited the autophagosome-lysosome fusion to block the degradation of autophagosomes, which aggravated Cd-induced cytotoxicity in rPT cells.


Assuntos
Autofagia/efeitos dos fármacos , Cádmio/toxicidade , Túbulos Renais Proximais/citologia , Animais , Autofagossomos/efeitos dos fármacos , Cálcio/metabolismo , Células Cultivadas , Citosol/metabolismo , Lisossomos/efeitos dos fármacos , Masculino , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas de Ligação a RNA/metabolismo , Ratos , Ratos Sprague-Dawley , Proteínas rab de Ligação ao GTP/metabolismo
11.
Chem Biol Interact ; 260: 219-231, 2016 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-27717697

RESUMO

Puerarin (PU) is a potent free radical scavenger with a protective effect in nephrotoxin-mediated oxidative damage. Here, we show a novel molecular mechanism by which PU exerts its anti-apoptotic effects in cadmium (Cd)-exposed primary rat proximal tubular (rPT) cells. Morphological assessment and flow cytometric analysis revealed that PU significantly decreased Cd-induced apoptotic cell death of rPT cells. Administration of PU protected cells against Cd-induced depletion of mitochondrial membrane potential (ΔΨm) and lipid peroxidation. Cd-mediated mitochondrial permeability transition pore (MPTP) opening, disruption of mitochondrial ultrastructure, mitochondrial cytochrome c (cyt-c) release, caspase-3 activation and subsequently poly ADP-ribose polymerase (PARP) cleavage could be effectively blocked by the addition of PU. Moreover, up-regulation of Bcl-2 and down-regulation of Bax and hence increased Bcl-2/Bax ratio were observed with the PU administration. In addition, PU reversed Cd-induced ATP depletion by restoring ΔΨm to affect ATP production and by regulating expression levels of ANT-1 and ANT-2 to improve ATP transport. In summary, PU inhibited Cd-induced apoptosis in rPT cells by ameliorating the mitochondrial dysfunction.


Assuntos
Cádmio/toxicidade , Isoflavonas/farmacologia , Túbulos Renais Proximais/patologia , Mitocôndrias/metabolismo , Substâncias Protetoras/farmacologia , Translocador 1 do Nucleotídeo Adenina/genética , Translocador 1 do Nucleotídeo Adenina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citocromos c/metabolismo , Ativação Enzimática/efeitos dos fármacos , Espaço Intracelular/metabolismo , Isoflavonas/administração & dosagem , Túbulos Renais Proximais/efeitos dos fármacos , Túbulos Renais Proximais/ultraestrutura , Malondialdeído/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Modelos Biológicos , Poli(ADP-Ribose) Polimerases/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo
12.
J Inorg Biochem ; 164: 99-109, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27665314

RESUMO

Ca2+ signaling plays a vital role in regulating apoptosis and autophagy. We previously proved that cytosolic Ca2+ overload is involved in cadmium (Cd)-induced apoptosis in rat proximal tubular (rPT) cells, but the source of elevated cytosolic Ca2+ concentration ([Ca2+]c) and the effect of potential subcellular Ca2+ redistribution on apoptosis and autophagy remain to be elucidated. Firstly, data showed that Cd-induced elevation of [Ca2+]c was primarily generated intracellularly. Moreover, elevations of [Ca2+]c and mitochondrial Ca2+ concentration ([Ca2+]mit) with depletion of endoplasmic reticulum (ER) Ca2+ levels ([Ca2+]ER) were revealed in Cd-treated rPT cells, but this subcellular Ca2+ redistribution was significantly suppressed by 2-Aminoethoxydiphenyl borate (2-APB). Elevated inositol 1,4,5-trisphosphate (IP3) levels with up-regulated IP3 receptor (IP3R) protein levels were shown in Cd-exposed cells, confirming that IP3R-mediated ER Ca2+ release results in the elevation of [Ca2+]c. Up-regulated sequestosome 1 (p62) protein levels and autophagic flux assay demonstrated that Cd impaired autophagic degradation, while N-acetylcysteine (NAC) markedly attenuated Cd-induced p62 and microtubule-associated protein 1 light chain 3-II (LC3-II) accumulation, implying that the inhibition of autophagic flux was due to oxidative stress. Furthermore, pharmacological modulation of [Ca2+]c with 1,2-Bis (2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM) and 2-APB alleviated Cd-mediated apoptosis, inhibition of autophagic degradation and subsequent cytotoxicity, while thapsigargin (TG) had the opposite regulatory effect on them. In summary, cytosolic calcium overload originated from IP3R-mediated ER Ca2+ release has a negative impact on Cd nephrotoxicity through its promotion of apoptosis and inhibition of autophagic flux.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Cádmio/farmacologia , Cálcio/metabolismo , Retículo Endoplasmático/metabolismo , Túbulos Renais Proximais/metabolismo , Animais , Túbulos Renais Proximais/citologia , Ratos
13.
Biol Trace Elem Res ; 174(1): 166-176, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27116952

RESUMO

Previous study has demonstrated that mitochondrial-dependent apoptotic pathway is involved in the nephroprotective effect of puerarin (PU) against lead-induced cytotoxicity in primary cultures of rat proximal tubular (rPT) cells. To further clarify how PU exerts its antiapoptotic effects, this study was designed to investigate the role of mitochondrial permeability transition (MPT) and subsequent apoptotic events in the process of PU against Pb-induced cytotoxicity in rPT cells. The results showed that Pb-mediated mitochondrial permeability transition pore (MPTP) opening together with mitochondrial cytochrome c release, activations of caspase-9 and caspase-3, and subsequent poly-ADP-ribose polymerase (PARP) cleavage can be effectively blocked by the addition of PU. Simultaneously, upregulation and downregulation of Bcl-2 and Bax with increased Bcl-2/Bax ratio due to PU administration further alleviated Pb-induced mitochondrial apoptosis. Moreover, PU can reverse Pb-induced ATP depletion by restoring mitochondrial fragmentation to affect ATP production and by regulating expression levels of ANT-1 and ANT-2 to improve ATP transport. In summary, PU produced a significant protection against Pb-induced mitochondrial apoptosis in rPT cells by inhibiting MPTP opening to ameliorate the mitochondrial dysfunction.


Assuntos
Apoptose/efeitos dos fármacos , Isoflavonas/farmacologia , Túbulos Renais Proximais/metabolismo , Chumbo/toxicidade , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial , Animais , Células Cultivadas , Proteínas de Transporte da Membrana Mitocondrial/antagonistas & inibidores , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Cultura Primária de Células , Ratos
14.
Arch Toxicol ; 90(5): 1193-209, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26082307

RESUMO

Previous studies have already demonstrated that mitochondria play a key role in Pb-induced apoptosis in primary cultures of rat proximal tubular (rPT) cells. To further clarify the underlying mechanism of Pb-induced mitochondrial apoptosis, this study was designed to investigate the role of mitochondrial permeability transition (MPT) and its regulatory components in Pb-induced apoptosis in rPT cells. Mitochondrial permeability transition pore (MPTP) opening together with disruption of mitochondrial ultrastructure, translocation of cytochrome c from mitochondria to cytoplasm and subsequent caspase-3 activation were observed in this study, suggesting that MPT is involved in Pb-induced apoptosis in rPT cells. Simultaneously, Pb-induced caspase-3 activation and apoptosis can be significantly inhibited by three MPTP inhibitors (CsA, DIDS, BA), which target different regulatory components of MPTP (Cyp-D, VDAC, ANT), respectively, demonstrating that Cyp-D, VDAC and ANT participate in MPTP regulation during lead exposure. Moreover, decreased ATP levels and increased ADP/ATP ratio induced by lead treatment can be significantly reversed by BA, indicating that Pb-mediated ANT dysfunction resulted in ATP depletion. In addition, up-regulation of VDAC-1, ANT-1 together with down-regulation of Cyp-D, VDAC-2 and ANT-2 at both the levels of transcription and translation were revealed in rPT cells under lead exposure conditions. In conclusion, Pb-mediated mitochondrial apoptosis in rPT cells is dependent on MPTP opening. Different expression levels in each isoform of three regulatory components contribute to alteration in their functions, which may promote the MPTP opening.


Assuntos
Apoptose/efeitos dos fármacos , Túbulos Renais Proximais/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Proteínas de Transporte da Membrana Mitocondrial/efeitos dos fármacos , Compostos Organometálicos/toxicidade , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Caspase 3/metabolismo , Células Cultivadas , Citocromos c/metabolismo , Relação Dose-Resposta a Droga , Ativação Enzimática , Regulação da Expressão Gênica , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/ultraestrutura , Masculino , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Compostos Organometálicos/metabolismo , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
15.
J Vet Sci ; 16(4): 439-46, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26040614

RESUMO

To evaluate the effects of chelated Zn/Cu/Mn on redox status, immune responses and hoof health in lactating Holstein cows, 48 head in early lactation were divided into healthy or lame groups according to their gait score. Cows were fed the same amount of Zn/Cu/Mn as sulfate salts or in chelated forms for 180 days, and foot-and-mouth disease (FMD) vaccine was injected at day 90. The results showed that lame cows had lower antioxidant function, serum Zn/Mn levels, hair Cu levels, and hoof hardness. Moreover, increased antioxidant status, FMD antibody titers, serum and hair levels of Zn/Cu/Mn, and hoof hardness and decreased milk fat percent and arthritis biomarkers were observed in cows fed chelated Zn/Cu/Mn. In summary, supplementation with chelated Zn/Cu/Mn improved antioxidant status and immune responses, reduced arthritis biomarkers, and increased accumulation of Zn/Cu/Mn in the body and hoof hardness in dairy cows.


Assuntos
Doenças dos Bovinos/tratamento farmacológico , Terapia por Quelação/veterinária , Cobre/uso terapêutico , Coxeadura Animal/tratamento farmacológico , Manganês/uso terapêutico , Zinco/uso terapêutico , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Suplementos Nutricionais/análise , Feminino , Casco e Garras , Imunidade Inata , Coxeadura Animal/etiologia , Metionina/análogos & derivados , Metionina/uso terapêutico , Oxirredução , Sulfatos/uso terapêutico
16.
Toxicology ; 333: 137-46, 2015 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-25921245

RESUMO

Previous studies have shown that cytosolic Ca(2+) ([Ca(2+)]c) overload was involved in Pb-induced apoptosis in primary cultures of rat proximal tubular (rPT) cells, but the source of elevated Ca(2+) and the effect of potential subcellular Ca(2+) redistribution on apoptosis are still unknown. In this study, variations of [Ca(2+)]c in two culture media (Ca(2+)-containing and Ca(2+)- free) were analyzed, indicating that Pb-induced elevation of [Ca(2+)]c was primarily generated intracellularly. Fluo-4-AM, dihydro-Rhod-2-AM and Mag-Fluo-4-AM was loaded to Pb-exposed rPT cells to monitor the imaging of Ca(2+) concentrations in the cytoplasm ([Ca(2+)]c), mitochondria ([Ca(2+)]mit) and endoplasmic reticulum (ER) ([Ca(2+)]ER), respectively, under the confocal microscope. Data indicate that elevations of [Ca(2+)]c and [Ca(2+)]mit with depletion of [Ca(2+)]ER were revealed in Pb-treated rPT cells, but this subcellular Ca(2+) redistribution could be significantly suppressed by 2-APB, a specific inhibitor of inositol 1,4,5-trisphosphate receptor (IP3R) that functions to release Ca(2+) from ER stores. Simultaneously, Pb-mediated mitochondrial Ca(2+) overload can be partially suppressed by the cytosolic Ca(2+) chelator BAPTA-AM, suggesting that Ca(2+) uptake into mitochondria occurs via diverse pathways and ER Ca(2+) storage was the chief source. Furthermore, Pb-induced apoptosis was markedly inhibited by 2-APB and BAPTA-AM, respectively. Additionally, elevated IP3 levels with up-regulated IP3R-1 and IP3R-2 (mRNA and protein) levels were revealed in Pb-exposed rPT cells. In summary, IP3R-mediated ER Ca(2+) release promoted the elevations of [Ca(2+)]c and [Ca(2+)]mit in Pb-exposed rPT cells, which played a chief role in apoptosis induced by impaired calcium homeostasis.


Assuntos
Apoptose/efeitos dos fármacos , Sinalização do Cálcio/efeitos dos fármacos , Cálcio/metabolismo , Túbulos Renais Proximais/efeitos dos fármacos , Compostos Organometálicos/toxicidade , Animais , Compostos de Boro/farmacologia , Células Cultivadas , Quelantes/farmacologia , Citoplasma/metabolismo , Relação Dose-Resposta a Droga , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Homeostase , Inositol 1,4,5-Trifosfato/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/efeitos dos fármacos , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Microscopia Confocal , Microscopia de Fluorescência , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Cultura Primária de Células , Ratos Sprague-Dawley , Fatores de Tempo
17.
Biol Trace Elem Res ; 164(1): 43-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25534290

RESUMO

The objective of this study was to investigate correlations between oxidative stress, metabolism of mineral elements, and lameness in dairy cows. Forty multiparous Chinese Holstein dairy cows were selected and divided into two groups (healthy vs lame, n = 20) by gait score. The experiment lasted for 60 days and samples of hair, blood, and hoof were collected at days 0, 30, and 60 of experiment period, individually. Compared with healthy cows, elevation of MDA, CTX-II, COMP levels, and GSSG/GSH ratio together with depletion of SOD and MT levels in the serum were revealed in lame cows. Simultaneously, significant decreased contents of Zn, Cu, and Mn in the serum, hair, and hoof samples were shown in lame cows, but there was no obvious difference in contents of P, Mg, and Ca (except hoof Ca) in the serum, hair, and hoof between healthy and lame cows. In addition, histological examination and the hardness test demonstrated a poor hoof quality in lame cows. In summary, oxidative stress is implicated in the pathogenesis of lameness caused by imbalance of nutrients (especially selective minerals promoting healthy hoof growth) in dairy cows.


Assuntos
Doenças dos Bovinos/sangue , Doenças dos Bovinos/fisiopatologia , Coxeadura Animal/sangue , Coxeadura Animal/fisiopatologia , Minerais/sangue , Estresse Oxidativo/fisiologia , Animais , Bovinos , Doenças dos Bovinos/metabolismo , Cobre/sangue , Feminino , Coxeadura Animal/metabolismo , Manganês/sangue , Minerais/metabolismo , Zinco/sangue
18.
J Bone Miner Metab ; 33(1): 23-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24578216

RESUMO

The aim of this study was to investigate the effects of manganese (Mn) deficiency on chondrocyte development in tibia growth plate. Ninety 1-day-old Arbor Acres chicks were randomly divided into three groups and fed on control diet (60 mg Mn/kg diet) and manganese deficient diets (40 mg Mn/kg diet, manganese deficiency group I; 8.7 mg Mn/kg diet, manganese deficiency group II), respectively. The width of the proliferative zone of growth plate was measured by the microscope graticule. Chondrocyte apoptosis was estimated by TUNEL staining. Gene expression of p21 and Bcl-2, and expression of related proteins were analyzed by quantitative real time reverse transcription polymerase chain reaction and immunohistochemistry, respectively. Compared with the control group, manganese deficiency significantly decreased the proliferative zone width and Bcl-2 mRNA expression level, while significantly increased the apoptotic rates and the expression level of p21 gene in chondrocytes. The results indicate that manganese deficiency had a negative effect on chondrocyte development, which was mediated by the inhibition of chondrocyte proliferation and promotion of chondrocyte apoptosis.


Assuntos
Condrócitos/citologia , Manganês/deficiência , Tíbia/crescimento & desenvolvimento , Ração Animal , Animais , Apoptose , Diferenciação Celular , Galinhas , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Regulação da Expressão Gênica , Lâmina de Crescimento/citologia , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Manganês/química , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real
19.
Biomed Environ Sci ; 26(4): 258-67, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23534466

RESUMO

OBJECTIVE: To investigate the protective effects of quercetin on cadmium-induced cytotoxicity in primary cultures of rat proximal tubular (rPT) cells. METHODS: Primary cultures of rPT cells undergoing exponential growth were incubated with 1.0 µg/mL quercetin and/or cadmium (2.5, 5.0 µmol/L), in a serum-free medium at 37 °C at different time intervals. Commercial kits were used and flow cytometric analyses were performed on rPT cell cultures to assay apoptosis and oxidative stress. RESULTS: Exposure of rPT cells to cadmium acetate (2.5, 5.0 µmol/L) induced a decrease in cell viability, caused an increase in apoptotic rate and apoptotic morphological changes. Simultaneously, elevation of intracellular reactive oxygen species, malondialdehyde and calcium levels, depletion of mitochondrial membrane potential and intracellular glutathione, and inhibition of Na+, K+-ATPase, Ca2+-ATPase, glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) activities were revealed during the cadmium exposure of rPT cells. However, simultaneous supplementation with 1 µg/mL quercetin protected rPT cells against cadmium-induced cytotoxicity through inhibiting apoptosis, attenuating lipid peroxidation, renewing mitochondrial function and elevating the intracellular antioxidants (non-enzymatic and enzymic) levels. CONCLUSION: The present study has suggested that quercetin, as a widely distributed dietary antioxidant, contributes potentially to prevent cadmium-induced cytotoxicity in rPT cells.


Assuntos
Antioxidantes/uso terapêutico , Intoxicação por Cádmio/prevenção & controle , Cádmio/toxicidade , Túbulos Renais Proximais/efeitos dos fármacos , Quercetina/uso terapêutico , Animais , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Cálcio/metabolismo , ATPases Transportadoras de Cálcio/metabolismo , Células Cultivadas , Túbulos Renais Proximais/metabolismo , Malondialdeído/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Quercetina/farmacologia , Ratos , Espécies Reativas de Oxigênio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo
20.
Opt Lett ; 35(10): 1512-4, 2010 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-20479792

RESUMO

A multistep processing and reactive ion etching technique has been developed to fabricate optical channel waveguides based on deoxyribonucleic acid-cetyltrimethylammonium biopolymer material. The channel waveguides exhibit excellent single-mode output and high confinement of light because of the sharp waveguide profile with very smooth surfaces and vertical sidewalls. The measurement results show that these channel waveguides have low propagation losses and small polarization dependent losses at 633, 1310, and 1550 nm wavelengths.


Assuntos
Biopolímeros/química , Compostos de Cetrimônio/química , DNA/química , Absorção , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Fenômenos Ópticos , Polimetil Metacrilato/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA