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1.
Front Vet Sci ; 8: 692221, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34386537

RESUMO

In dogs, circumanal tumors are the third most common skin neoplasm. Circumanal gland adenomas (CAGAs) have a good prognosis. Contrastingly, circumanal gland adenocarcinomas (CAGAC) have high relapse rates and may be metastatic. This study aimed to investigate the utility of thermal imaging as an ancillary modality for the diagnosis of canine CAGA and CAGAC. We analyzed the following parameters: SpT, temperature measured at the tumor center; SpNT, temperature measured at a healthy sphincter skin spot distant from the tumor; TA, temperature measured at a tumor-encompassing ellipse-shaped area; and NTA, temperature measured at an ellipse-shaped area of the healthy sphincter skin distant from the tumor. In CAGAs, the mean SpT and SpNT temperature values differed by -1.45°C (p < 0.01) while the mean TA and NTA temperature values differed by -0.96°C (p < 0.05). In CAGACs, mean SpT and SpNT temperatures differed by -1.71°C (p < 0.01) while the mean TA and NTA temperatures differed by -1.69°C (p < 0.01). The mean SpT and TA temperature values measured in CAGAs and CAGACs differed by -0.10°C (p = 0.87) and 0.52°C (p = 0.38), respectively. Both tumors were colder than healthy sphincter skin. However, a substantial number of CAGACs were colder than CAGAs. Temperature differences ≥ 1°C between tumors and healthy sphincter skin increased the probability of CAGAC diagnosis by 17.45%. Thermal imaging allowed discrimination between healthy and tumoral tissues; therefore, it could be a good ancillary diagnostic modality.

2.
Phys Rev Lett ; 126(25): 256801, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34241527

RESUMO

We construct multimode viscous hydrodynamics for one-dimensional spinless electrons. Depending on the scale, the fluid has six (shortest lengths), four (intermediate, exponentially broad regime), or three (asymptotically long scales) hydrodynamic modes. Interaction between hydrodynamic modes leads to anomalous scaling of physical observables and waves propagating in the fluid. In the four-mode regime, all modes are ballistic and acquire Kardar-Parisi-Zhang (KPZ)-like broadening with asymmetric power-law tails. "Heads" and "tails" of the waves contribute equally to thermal conductivity, leading to ω^{-1/3} scaling of its real part. In the three-mode regime, the system is in the universality class of a classical viscous fluid [O. Narayan and S. Ramaswamy, Anomalous Heat Conduction in One-Dimensional Momentum-Conserving Systems, Phys. Rev. Lett. 89, 200601 (2002).PRLTAO0031-900710.1103/PhysRevLett.89.200601, H. Spohn, Nonlinear fluctuating hydrodynamics for anharmonic chains, J. Stat. Phys. 154, 1191 (2014).JSTPBS0022-471510.1007/s10955-014-0933-y]. Self-interaction of the sound modes results in a KPZ-like shape, while the interaction with the heat mode results in asymmetric tails. The heat mode is governed by Levy flight distribution, whose power-law tails give rise to ω^{-1/3} scaling of heat conductivity.

4.
Front Cell Neurosci ; 13: 334, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31402853

RESUMO

Müller glial cells (MGC) are stem cells in the retina. Although their regenerative capacity is very low in mammals, the use of MGC as stem cells to regenerate photoreceptors (PHRs) during retina degenerations, such as in retinitis pigmentosa, is being intensely studied. Changes affecting PHRs in diseased retinas have been thoroughly investigated; however, whether MGC are also affected is still unclear. We here investigated whether MGC in retinal degeneration 1 (rd1) mouse, an animal model of retinitis pigmentosa, have impaired stem cell properties or structure. rd1 MGC showed an altered morphology, both in culture and in the whole retina. Using mixed neuron-glial cultures obtained from newborn mice retinas, we determined that proliferation was significantly lower in rd1 than in wild type (wt) MGC. Levels of stem cell markers, such as Nestin and Sox2, were also markedly reduced in rd1 MGC compared to wt MGC in neuron-glial cultures and in retina cryosections, even before the onset of PHR degeneration. We then investigated whether neuron-glial crosstalk was involved in these changes. Noteworthy, Nestin expression was restored in rd1 MGC in co-culture with wt neurons. Conversely, Nestin expression decreased in wt MGC in co-culture with rd1 neurons, as occurred in rd1 MGC in rd1 neuron-glial mixed cultures. These results imply that MGC proliferation and stem cell markers are reduced in rd1 retinas and might be restored by their interaction with "healthy" PHRs, suggesting that alterations in rd1 PHRs lead to a disruption in neuron-glial crosstalk affecting the regenerative potential of MGC.

5.
Phys Rev Lett ; 122(20): 206801, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31172760

RESUMO

We study thermal conductivity for one-dimensional electronic fluids. The many-body Hilbert space is partitioned into bosonic and fermionic sectors that carry the thermal current in parallel. For times shorter than the bosonic umklapp time, the momenta of Bose and Fermi components are separately conserved, giving rise to the ballistic heat propagation and imaginary heat conductivity proportional to T/iω. The real part of thermal conductivity is controlled by decay processes of fermionic and bosonic excitations, leading to several regimes in frequency dependence. At lowest frequencies or longest length scales, the thermal transport is dominated by Lévy flights of low-momentum bosons that lead to a fractional scaling, ω^{-1/3} and L^{1/3}, of heat conductivity with the frequency ω and system size L, respectively.

7.
Theriogenology ; 119: 121-130, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30006127

RESUMO

Cytochrome B is an important polypeptide of the mitochondria helpful in energy metabolism through oxidative phosphorylation. Cytochrome B plays an immense role in the reproduction of animals and due to its mutation prone nature, it can affect the basic physiology of animals. Cytochrome B affects reproductive system in males and equally plays an important role in transferring and providing energy in the development of the embryo, zygote, and oocytes precisely in females. The present study was conducted on Ghungroo pig to study their molecular and reproductive traits and the effect of the cytochrome B gene in the female reproduction of the Ghungroo pig. Although studies are available for cytochrome B gene analysis for evolutionary studies through phylogenetic analysis. This is the first report for the study of Cytochrome B gene on reproduction in pigs. Cytochrome B gene was sequenced and seven SNPs were observed out of which three were non-synonymous. INDEL mutation was detected in Variant B which had lead to Frame Shift mutation resulting in a stop codon AGA. The effect in the reproductive traits of the sow was studied due to the occurrence of nucleotide substitution. Bioinformatics analysis (I-mutant, PROVEAN, and SIFT) had revealed that the mutations were deleterious for the mutant type. Mutation leading to alterations in post-translational modification sites as phosphorylation site, leucine-rich nuclear export signal, occurrence of transmembrane helices, arginine and lysine peptide cleavage site for the mutant variant had resulted in a reduced physiological response. 3 D protein structure, (predicted through bioinformatics analysis) for cytochrome B has revealed distinct structural differences in mutated form with truncated protein by RMSD analysis through TM-Align software. Associated studies of genotype variants with reproductive traits have revealed the significant effect of variants of cytochrome B gene on reproductive traits namely litter size at first, second and third furrowing, piglet mortality, age at first furrowing and furrowing interval. Mitochondrial gene as Cytochrome B variants might be used as a marker for studying female reproduction of Ghungroo sow in future.


Assuntos
Citocromos b/genética , Polimorfismo de Nucleotídeo Único , Suínos/genética , Animais , Feminino , Regulação da Expressão Gênica/fisiologia , Marcadores Genéticos , Modelos Moleculares , Gravidez , Conformação Proteica , Processamento de Proteína Pós-Traducional , Suínos/fisiologia
8.
PLoS One ; 12(11): e0187877, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29136033

RESUMO

There is a high prevalence of vitamin D insufficiency and deficiency worldwide likely because of both limited sun-exposure and inadequate dietary intake. Meat, including pork, is not typically considered a dietary source of vitamin D, possibly because of management practices that raise pigs in confinement. This experiment determined the vitamin D content of loin and subcutaneous adipose tissue in sun-exposed finisher pigs. Two separate groups of pigs were used. The first group (28 white Landrace-Duroc) was assigned at random to either sunlight exposure (SUN) in spring and summer or confinement per standard practice (Control). The second (24 Yorkshire-Duroc-Landrace) underwent the same exposure protocol but was exposed in summer and fall or assigned to control (Control). A subsample of five SUN and four Control pigs, matched for weight and body condition score, was selected for slaughter from each group. Pigs (n = 10 SUN, n = 8 Control) had blood drawn for analysis of 25(OH)D3 concentration before/after sun exposure or control, and tissue samples were taken at slaughter for analysis of tissue vitamin D3 and 25(OH)D3 concentration. Three random samples from a single loin chop and surrounding adipose were collected and analyzed. Serum concentrations of 25(OH)D3 did not differ (P≥0.376) between treatments prior to sun exposure in either group, but was increased (time*treatment interaction, P<0.001) with SUN exposure. Total vitamin D content (D3 plus 25(OH)D3) of loin tissue was increased (P < 0.001) with sun exposure and averaged 0.997±0.094 µg/100g and 0.348±0.027 µg/100g for sun and control pigs, respectively. While exposure to sunlight increased (P = 0.003) tissue content of 25(OH) D in subcutaneous adipose tissue, vitamin D3 content was similar between treatments (P = 0.56). Sunlight exposure in pigs increased the vitamin D content of loin, and may provide an additional source of dietary vitamin D.


Assuntos
Produtos da Carne/análise , Valor Nutritivo , Luz Solar , Vitamina D/análise , Animais , Suínos , Vitamina D/sangue
9.
J Neuroimmunol ; 313: 145-151, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-28992974

RESUMO

Benzodiazepines are psychoactive drugs and some of them also affect immune cells. We here characterized the inflammatory and infiltrating immune cells in the central nervous system (CNS) during the acute phase of experimental autoimmune encephalomyelitis (EAE) in animals treated with Diazepam. Also, we evaluated the expression of Translocator Protein (18kDa) (TSPO), which is a biomarker of neuroinflammatory diseases. The results indicate that Diazepam exerts protective effects on EAE development, decreasing the incidence of the disease and reducing the number of inflammatory cells in CNS, with a concomitant decrease of TSPO levels in brain tissue and CNS inflammatory CD11b+ cells.


Assuntos
Antígeno CD11b/metabolismo , Proteínas de Transporte/metabolismo , Sistema Nervoso Central/efeitos dos fármacos , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/patologia , Hipnóticos e Sedativos/uso terapêutico , Receptores de GABA-A/metabolismo , Animais , Proteínas de Transporte/genética , Citocinas/metabolismo , Diazepam/uso terapêutico , Modelos Animais de Doenças , Linfócitos/patologia , Macrófagos/patologia , Monócitos/patologia , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Receptores de GABA-A/genética , Fatores de Tempo
10.
J Biol Chem ; 291(32): 16541-52, 2016 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-27284006

RESUMO

The homomeric α7 nicotinic receptor (nAChR) is one of the most abundant nAChRs in the central nervous system where it contributes to cognition, attention, and working memory. α7 nAChR is also present in lymphocytes, dendritic cells (DCs), and macrophages and it is emerging as an important drug target for intervention in inflammation and sepsis. Natural killer (NK) cells display cytotoxic activity against susceptible target cells and modulate innate and adaptive immune responses through their interaction with DCs. We here show that human NK cells also express α7 nAChR. α7 nAChR mRNA is detected by RT-PCR and cell surface expression of α7 nAChR is detected by confocal microscopy and flow cytometry using α-bungarotoxin, a specific antagonist. Both mRNA and protein levels increase during NK stimulation with cytokines (IL-12, IL-18, and IL-15). Exposure of cytokine-stimulated NK cells to PNU-282987, a specific α7 nAChR agonist, increases intracellular calcium concentration ([Ca(2+)]i) mainly released from intracellular stores, indicating that α7 nAChR is functional. Moreover, its activation by PNU-282987 plus a specific positive allosteric modulator greatly enhances the Ca(2+) responses in NK cells. Stimulation of NK cells with cytokines and PNU-282987 decreases NF-κB levels and nuclear mobilization, down-regulates NKG2D receptors, and decreases NKG2D-dependent cell-mediated cytotoxicity and IFN-γ production. Also, such NK cells are less efficient to trigger DC maturation. Thus, our results demonstrate the anti-inflammatory role of α7 nAChR in NK cells and suggest that modulation of its activity in these cells may constitute a novel target for regulation of the immune response.


Assuntos
Sinalização do Cálcio/imunologia , Citocinas/imunologia , Células Matadoras Naturais/imunologia , Receptor Nicotínico de Acetilcolina alfa7/imunologia , Benzamidas/farmacologia , Compostos Bicíclicos com Pontes/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Feminino , Humanos , Células Matadoras Naturais/citologia , Masculino , NF-kappa B/imunologia , Subfamília K de Receptores Semelhantes a Lectina de Células NK/imunologia
11.
Leuk Lymphoma ; 56(4): 1115-22, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25156469

RESUMO

Chronic lymphocytic leukemia (CLL) is the main cause of autoimmune hemolytic anemia (AHA). However, the cellular basis underlying this strong association remains unclear. We previously demonstrated that leukemic B cells from patients with CLL recognize the erythrocyte protein Band 3, a prevalent autoantigen in AHA. Here we show that the major binding site of Band 3 on leukemic cells is an extrinsic protein identified as high-mobility group nucleosome binding protein 2 (HMGN2), a nucleosome-interacting factor which has not been previously reported at the cell surface. T lymphocytes do not express HMGN2 or bind Band 3. Removal of HMGN2 from the cell membrane abrogated the capacity of Band 3-pulsed CLL cells to induce CD4 + T cell proliferation. We conclude that surface HMGN2 in leukemic B cells is involved in Band 3 binding, uptake and presentation to CD4 + T lymphocytes, and as such may favor the initiation of AHA secondary to CLL.


Assuntos
Anemia Hemolítica Autoimune/metabolismo , Linfócitos B/metabolismo , Membrana Celular/metabolismo , Proteína HMGN2/metabolismo , Leucemia Linfocítica Crônica de Células B/metabolismo , Idoso , Anemia Hemolítica Autoimune/etiologia , Proteína 1 de Troca de Ânion do Eritrócito/metabolismo , Sítios de Ligação , Linhagem Celular Tumoral , Células Cultivadas , Feminino , Citometria de Fluxo , Humanos , Concentração de Íons de Hidrogênio , Leucemia Linfocítica Crônica de Células B/complicações , Masculino , Microscopia Confocal , Microscopia de Fluorescência , Pessoa de Meia-Idade , Ligação Proteica
12.
Biochim Biophys Acta ; 1841(1): 151-61, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24120575

RESUMO

Cadmium is known to harm rat testis by causing the dose-dependent apoptotic or necrotic death of seminiferous epithelium cells. Here we investigated how this affects the lipids with long-chain (C18-C22) and very-long-chain (C24-C32) polyunsaturated fatty acids (VLCPUFA) typical of spermatogenic and Sertoli cells. A severe acute inflammatory reaction resulted from the massive necrotic death of these cells two days after a single high (4mg/kg) dose of CdCl2. This led to the conversion of most testicular glycerophospholipids to diradylglycerols (DRG) and free fatty acids (FFA) and of most sphingomyelins to ceramides (Cer). By day 30 the testis weight had decreased three-fold. The DRG and FFA had been metabolized but, unexpectedly, ceramides persisted. Also slow to disappear were VLCPUFA-containing triacylglycerols from former germ cells and ether-linked triglycerides and cholesteryl esters (CE) from former Sertoli cells. Similar results were observed 30 and 45days after administering repeated small non pro-inflammatory CdCl2 doses (1mg/kg). At day 30 after both treatments, an amorphous material replaced the original seminiferous tubules and the interstitium was populated by macrophages. Species of CE and ether-linked triglycerides containing fatty acids other than VLCPUFA steadily accumulated in the irreversibly damaged testis, a manifestation of the activity of these cells. The long-term permanence of original VLCPUFA-containing neutral lipids, especially ceramides, indicates that these phagocytes were slow to clear out the acellular material contained in seminiferous tubules, pointing to a form of silent chronic inflammation as an additional outcome of the multifactorial commotion caused in the testis by experimentally administered cadmium.


Assuntos
Cloreto de Cádmio/toxicidade , Ceramidas/metabolismo , Ácidos Graxos Insaturados/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Túbulos Seminíferos/metabolismo , Células de Sertoli/metabolismo , Triglicerídeos/metabolismo , Animais , Cádmio/toxicidade , Ésteres do Colesterol , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Necrose/induzido quimicamente , Necrose/metabolismo , Necrose/patologia , Ratos , Ratos Wistar , Túbulos Seminíferos/patologia , Células de Sertoli/patologia , Fatores de Tempo
13.
Invest New Drugs ; 30(5): 1830-40, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21887502

RESUMO

Aplidin is a novel cyclic depsipeptide, currently in Phase II/III clinical trials for solid and hematologic malignancies. The aim of this study was to evaluate the effect of Aplidin in chronic lymphocytic leukemia (CLL), the most common leukemia in the adult. Although there have been considerable advances in the treatment of CLL over the last decade, drug resistance and immunosuppression limit the use of current therapy and warrant the development of novel agents. Here we report that Aplidin induced a dose- and time-dependent cytotoxicity on peripheral blood mononuclear cells (PBMC) from CLL patients. Interestingly, Aplidin effect was markedly higher on monocytes compared to T lymphocytes, NK cells or the malignant B-cell clone. Hence, we next evaluated Aplidin activity on nurse-like cells (NLC) which represent a cell subset differentiated from monocytes that favors leukemic cell progression through pro-survival signals. NLC were highly sensitive to Aplidin and, more importantly, their death indirectly decreased neoplasic clone viability. The mechanisms of Aplidin-induced cell death in monocytic cells involved activation of caspase-3 and subsequent PARP fragmentation, indicative of death via apoptosis. Aplidin also showed synergistic activity when combined with fludarabine or cyclophosphamide. Taken together, our results show that Aplidin affects the viability of leukemic cells in two different ways: inducing a direct effect on the malignant B-CLL clone; and indirectly, by modifying the microenvironment that allows tumor growth.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Depsipeptídeos/farmacologia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/patologia , Leucócitos Mononucleares/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Monócitos/patologia , Idoso , Idoso de 80 Anos ou mais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ciclofosfamida/administração & dosagem , Depsipeptídeos/administração & dosagem , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Feminino , Humanos , Leucemia Linfocítica Crônica de Células B/sangue , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/patologia , Masculino , Pessoa de Meia-Idade , Monócitos/metabolismo , Peptídeos Cíclicos , Poli(ADP-Ribose) Polimerases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Vidarabina/administração & dosagem , Vidarabina/análogos & derivados
14.
Anaesthesia ; 66(12): 1146-59, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22070585

RESUMO

There has been a great deal of progress in our understanding and management of rheumatoid arthritis in recent years. The peri-operative management of rheumatoid arthritis patients can be challenging and anaesthetists need to be familiar with recent developments and potential risks of this multi system disease.


Assuntos
Anestesia/métodos , Artrite Reumatoide/cirurgia , Manuseio das Vias Aéreas , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/imunologia , Autoanticorpos/sangue , Produtos Biológicos/uso terapêutico , Citocinas/sangue , Humanos , Metotrexato/uso terapêutico
15.
Biochimie ; 92(12): 1886-94, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20850501

RESUMO

Rat spermatozoa main lipid classes and their fatty acids were studied to assess their possible changes in capacitation and the acrosomal reaction (AR), induced in vitro. Capacitation-associated protein tyrosine phosphorylation, and the efflux of 30% of the total cholesterol from gametes to the medium, took place concomitantly with the release of a similar percentage, i.e., a larger amount, of the total phospholipid, mostly after hydrolysis of the major choline glycerophospholipids (CGP). Main medium lipid metabolites after capacitation were lyso-CGP and polyenoic fatty acids typical of CGP (22:4n-9, 22:5n-6), as free fatty acids (FFA). The AR, induced by a calcium ionophore, resulted in further phospholipid loss, but the produced metabolites remained in the gametes. CGP decrease in AR accounted for some additional FFA and lyso-CGP, but mostly for (22:5n-6-rich) diglycerides. Hydrolysis of sphingomyelins (SM) to ceramides also occurred, mostly affecting species with very long chain polyenoic fatty acids. Quantitatively, CGP and SM were the lipid classes decreasing the most after capacitation and AR, respectively. The massive cholesterol and phospholipid loss from the gametes during capacitation is thus associated with protein phosphorylation, a function that has been located to the sperm tail. The lipid metabolites produced during AR, by accumulating in the gamete heads, could be implicated in sperm-oocyte interactions.


Assuntos
Reação Acrossômica/fisiologia , Fosfatidilcolinas/metabolismo , Capacitação Espermática/fisiologia , Espermatozoides/metabolismo , Esfingomielinas/metabolismo , Animais , Ceramidas/metabolismo , Colesterol/metabolismo , Ácidos Graxos/metabolismo , Feminino , Metabolismo dos Lipídeos/fisiologia , Masculino , Fosfolipídeos/metabolismo , Ratos , Ratos Wistar
16.
Biochimie ; 92(12): 1778-86, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20831891

RESUMO

Sphingolipids from rodent testis and spermatozoa are known to contain non-hydroxylated (N-) and 2-hydroxylated (2-OH) very-long-chain polyunsaturated fatty acids (VLCPUFA). In this study, the contribution of species with each type of fatty acids to the total ceramides (Cer) and sphingomyelins (SM) was investigated in rat and mouse testis and in rat spermatozoa. The major VLCPUFA in both lipids of testis were N- and 2-OH versions of 28:4n-6, 30:5n-6 and 32:5n-6 in the rat, and predominantly of 30:5n-6 in the mouse. Absent altogether from rat pre-puberal testes, SM and Cer with N-VLCPUFA appeared 10 days earlier than those with 2-OH VLCPUFA in postnatal development, in association with germ cell differentiation. Conversely, in adult fertile rats that were gradually deprived of germ cells in vivo after treatment with doxorubicin, SM and Cer with N-VLCPUFA decreased earlier than their 2-OH counterparts, and neither was present in aspermatogenic testes. In rat epididymal spermatozoa, the content of Cer prevailed over that of SM and 2-OH VLCPUFA prevailed over N-VLCPUFA in both lipids. In mature gametes, the acrosomal reaction resulted in an almost complete hydrolysis of the species of SM that contain both types of VLCPUFA to produce the corresponding Cer. Ceramides are biosynthetic precursors of SM in the testis, but themselves final products in spermatozoa. VLCPUFA-rich SM and Cer are thus produced in germ cells with the teleological objective of fulfilling their ultimate physiological role in spermatozoa that are apt and ready to fertilize an oocyte.


Assuntos
Ceramidas/análise , Ácidos Graxos Insaturados/análise , Espermatozoides/química , Esfingomielinas/análise , Testículo/química , Reação Acrossômica/fisiologia , Animais , Antibióticos Antineoplásicos/farmacologia , Cromatografia em Camada Fina , Doxorrubicina/farmacologia , Feminino , Fertilização , Lipídeos/química , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Ratos , Ratos Wistar , Capacitação Espermática/fisiologia , Espermatozoides/fisiologia , Testículo/citologia , Testículo/efeitos dos fármacos , Fatores de Tempo
18.
Cancer Res ; 67(14): 6973-80, 2007 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-17638909

RESUMO

Doxorubicin disrupts spermatogenesis by causing apoptosis of spermatogonia and primary spermatocytes. The aim of this study was to examine the effect of this agent on adult rat testicular lipids and their fatty acids. A single dose (7.5 mg/kg) and a multidose regime (3 mg/kg once a week for 4 weeks) were evaluated. Both treatments resulted in the gradual loss of spermatogenic cells and determined a marked reduction in testicular size and weight 9 weeks after their start. Germ cell loss was accompanied by a decrease in phospholipids, including glycerophospholipids and sphingomyelin. Concomitantly, glycerophospholipids lost selectively their major polyunsaturated fatty acid (PUFA), 22:5n-6, and sphingomyelin lost its major very long-chain PUFA (VLCPUFA), 28:4n-6 and 30:5n-6. The molecular species from which the lost polyenes originated were thus a trait of germ cells. A transient peak of 16:0-ceramide was observed 48 h after the single dose. In both doxorubicin regimes, sphingomyelin and ceramide with reduced amounts of VLCPUFA after about 4 weeks and with no VLCPUFA after 9 weeks resulted. By contrast, triglycerides and especially cholesterol esters (CE) tended to accumulate in the testes undergoing germ cell death, probably in the surviving Sertoli cells, their fatty acid patterns suggesting that initially, these lipids retained part of the PUFA coming from, or no longer used for, the synthesis of germ cell glycerophospholipids. As the latter decreased, CE accumulated massively 9 weeks after starting doxorubicin treatment, 20:4n-6 becoming their major PUFA. Part of these CEs may derive from surviving steroidogenic cells.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Ácidos Graxos Insaturados/química , Lipídeos/química , Testículo/metabolismo , Animais , Ésteres do Colesterol/química , Glicerofosfolipídeos/química , Metabolismo dos Lipídeos , Masculino , Ratos , Ratos Wistar , Células de Sertoli/metabolismo , Esfingomielinas/metabolismo , Fatores de Tempo
19.
J Biol Chem ; 282(25): 18141-18150, 2007 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-17392276

RESUMO

Very long-chain polyunsaturated fatty acids (VLCPUFA) have previously been shown to be components of sphingomyelin (SM) of mammalian testis and spermatozoa. Here we examined the fatty acids of testicular ceramide (Cer) in comparison with those of SM in some mammals with a special focus on the rat testis. In bull, cat, dog, rabbit, mouse, and rat, VLCPUFA were found in both testicular lipids, Cer having a higher percentage of VLCPUFA than SM. Rat testis had the highest percentage of VLCPUFA in both lipids, the major ones being 28:4n-6 and 30:5n-6. VLCPUFA-containing SM and Cer occurred in cells located in the seminiferous tubules, where germ cells had a higher percentage of these species than Sertoli cells. Seminiferous tubule fractionation showed that SM and Cer of mitochondria and lysosomes had mostly saturates and negligible VLCPUFA, the latter being important in the SM and Cer of microsomes and other membrane fractions. VLCPUFA were absent from the SM and Cer of rat prepuberal testis, increased with the onset of spermatogenesis to account for nearly 15 and 40% of the total fatty acids of testicular SM and Cer, respectively, remained at those levels throughout the adult life of fertile rats and tended to decrease at advanced ages. Four conditions that lead to selective death of germ cells in vivo, namely experimental cryptorchidism, post-ischemic reperfusion, focalized x-ray irradiation and treatments with the antineoplasic drug doxorubicin, caused the VLCPUFA to disappear from the testicular SM and Cer of adult fertile rats, showing that these lipids are specific traits of spermatogenic cells.


Assuntos
Ceramidas/metabolismo , Ácidos Graxos Insaturados/metabolismo , Esfingomielinas/metabolismo , Animais , Ácidos Graxos , Fertilidade , Células Germinativas/metabolismo , Lipídeos/química , Masculino , Ratos , Ratos Wistar , Especificidade da Espécie , Espermatogênese , Testículo/metabolismo , Raios X
20.
Development ; 126(3): 577-86, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9876186

RESUMO

Wingless signaling plays a central role during epidermal patterning in Drosophila. We have analyzed zygotic requirements for Wingless signaling in the embryonic ectoderm by generating synthetic deficiencies that uncover more than 99% of the genome. We found no genes required for initial wingless expression, other than previously identified segmentation genes. In contrast, maintenance of wingless expression shows a high degree of zygotic transcriptional requirements. Besides known genes, we have identified at least two additional genomic regions containing new genes involved in Wingless maintenance. We also assayed for the zygotic requirements for Wingless response and found that no single genomic region was required for the cytoplasmic accumulation of Armadillo in the receiving cells. Surprisingly, embryos homozygously deleted for the candidate Wingless receptor, Dfrizzled2, showed a normal Wingless response. However, the Armadillo response to Wingless was strongly reduced in double mutants of both known members of the frizzled family in Drosophila, frizzled and Dfrizzled2. Based on their expression pattern during embryogenesis, different Frizzled receptors may play unique but overlapping roles in development. In particular, we suggest that Frizzled and Dfrizzled2 are both required for Wingless autoregulation, but might be dispensable for late Engrailed maintenance. While Wingless signaling in embryos mutant for frizzled and Dfrizzled2 is affected, Wingless protein is still internalized into cells adjacent to wingless-expressing cells. Incorporation of Wingless protein may therefore involve cell surface molecules in addition to the genetically defined signaling receptors of the frizzled family.


Assuntos
Proteínas de Drosophila , Drosophila/embriologia , Proteínas de Membrana/genética , Proteínas Proto-Oncogênicas/fisiologia , Transdução de Sinais/fisiologia , Animais , Receptores Frizzled , Proteínas de Membrana/fisiologia , Fenótipo , Ratos , Receptores Acoplados a Proteínas G , Receptores de Neurotransmissores/genética , Receptores de Neurotransmissores/fisiologia , Mapeamento por Restrição , Proteína Wnt1 , Zigoto/fisiologia
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