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排序方式: 共有318条查询结果,搜索用时 31 毫秒
41.
42.
Coenzyme Q10 restores oocyte mitochondrial function and fertility during reproductive aging 下载免费PDF全文
Assaf Ben‐Meir Eliezer Burstein Aluet Borrego‐Alvarez Jasmine Chong Ellen Wong Tetyana Yavorska Taline Naranian Maggie Chi Ying Wang Yaakov Bentov Jennifer Alexis James Meriano Hoon‐Ki Sung David L. Gasser Kelle H. Moley Siegfried Hekimi Robert F. Casper Andrea Jurisicova 《Aging cell》2015,14(5):887-895
Female reproductive capacity declines dramatically in the fourth decade of life as a result of an age‐related decrease in oocyte quality and quantity. The primary causes of reproductive aging and the molecular factors responsible for decreased oocyte quality remain elusive. Here, we show that aging of the female germ line is accompanied by mitochondrial dysfunction associated with decreased oxidative phosphorylation and reduced Adenosine tri‐phosphate (ATP) level. Diminished expression of the enzymes responsible for CoQ production, Pdss2 and Coq6, was observed in oocytes of older females in both mouse and human. The age‐related decline in oocyte quality and quantity could be reversed by the administration of CoQ10. Oocyte‐specific disruption of Pdss2 recapitulated many of the mitochondrial and reproductive phenotypes observed in the old females including reduced ATP production and increased meiotic spindle abnormalities, resulting in infertility. Ovarian reserve in the oocyte‐specific Pdss2‐deficient animals was diminished, leading to premature ovarian failure which could be prevented by maternal dietary administration of CoQ10. We conclude that impaired mitochondrial performance created by suboptimal CoQ10 availability can drive age‐associated oocyte deficits causing infertility. 相似文献
43.
N. Ya. Orlov T. G. Orlova A. R. Nezvetsky E. A. Burstein H. D. Bartunik 《Biochemistry (Moscow) Supplemental Series A: Membrane and Cell Biology》2011,5(2):121-127
cGMP-Specific phosphodiesterase (PDE6) is the key enzyme of the phototransduction system of vertebrate retinal rod outer segments
(ROS). The properties of PDE in extracts prepared by solubilization of bovine ROS in a high concentration (0.5% w/v) of detergent
n-nonyl-β-D-glucoside (NG) and following centrifugation (ROS-NG) have been studied. Basal PDE activity of the preparations
was low, but it greatly (>50-fold) increased (up to ∼20 μmol cGMP hydrolyzed/min per mg rhodopsin (R)) in the presence of
trypsin. In bleached GTPγS-containing preparations the specific PDE activity was dependent on ROS-NG concentration and was
half-maximal at about 0.8 μM of ROS G protein transducin (Gt). In dark-adapted GTPγS-containing ROS-NG preparations bleaching
of 0.2% of the rhodopsin resulted in half-maximal PDE activation. The same result was obtained when PDE in dark-adapted ROS-NG
preparations was activated by addition of a highly purified bleached rhodopsin solubilized by 0.5% solution of NG. The results
demonstrate that the presence of NG has no significant influence either on the properties of the main ROS phototrans-duction
system elements (R, Gt and PDE) or on the interaction between photoactivated R and Gt and suggest that the detergent NG can
be used for crystallization of the rhodopsin-transducin complex. 相似文献
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45.
Dembitzer FR Kinoshita Y Burstein D Phelps RG Beasley MB Garcia R Harpaz N Jaffer S Thung SN Unger PD Ghebrehiwet B Peerschke EI 《The journal of histochemistry and cytochemistry》2012,60(6):467-474
The gC1qR (i.e., gC1q receptor, gC1q binding protein, p32, p33) is a multifunctional cellular protein that interacts with components of the complement, kinin, and coagulation cascades and select microbial pathogens. Enhanced gC1qR expression has been reported in adenocarcinomas arising in a variety of organs. The present study compared gC1qR expression in normal, inflammatory, dysplastic, and malignant tissue of epithelial and mesenchymal origin. gC1qR expression was visualized in tissue sections by immunohistochemistry using the 60.11 monoclonal antibody (i.e., IgG(1) mouse monoclonal antibody directed against gC1qR) and the UltraVision LP Detection System. Sections were counterstained with hematoxylin and examined by light microscopy. Strongest gC1qR expression was noted in epithelial tumors of breast, prostate, liver, lung, and colon, as well as in squamous and basal cell carcinoma of the skin. However, increased gC1qR staining was appreciated also in inflammatory and proliferative lesions of the same cell types, as well as in normal continuously dividing cells. In contrast, tumors of mesenchymal origin generally stained weakly, with the exception of osteoblasts, which stained in both benign and malignant tissues. The data suggest that increased gC1qR expression may be a marker of benign and pathologic cell proliferation, particularly in cells of epithelial origin, with potential diagnostic and therapeutic applications. 相似文献
46.
Michelle T. Burstein Pavlo Kyryakov Adam Beach Vincent R. Richard Olivia Koupaki Alejandra Gomez-Perez Anna Leonov Sean Levy Forough Noohi Vladimir I. Titorenko 《Cell cycle (Georgetown, Tex.)》2012,11(18):3443-3462
Our studies revealed that LCA (lithocholic bile acid) extends yeast chronological lifespan if added to growth medium at the time of cell inoculation. We also demonstrated that longevity in chronologically aging yeast is programmed by the level of metabolic capacity and organelle organization that they developed before entering a quiescent state and, thus, that chronological aging in yeast is likely to be the final step of a developmental program progressing through at least one checkpoint prior to entry into quiescence. Here, we investigate how LCA influences longevity and several longevity-defining cellular processes in chronologically aging yeast if added to growth medium at different periods of the lifespan. We found that LCA can extend longevity of yeast under CR (caloric restriction) conditions only if added at either of two lifespan periods. One of them includes logarithmic and diauxic growth phases, whereas the other period exists in early stationary phase. Our findings suggest a mechanism linking the ability of LCA to increase the lifespan of CR yeast only if added at either of the two periods to its differential effects on various longevity-defining processes. In this mechanism, LCA controls these processes at three checkpoints that exist in logarithmic/diauxic, post-diauxic and early stationary phases. We therefore hypothesize that a biomolecular longevity network progresses through a series of checkpoints, at each of which (1) genetic, dietary and pharmacological anti-aging interventions modulate a distinct set of longevity-defining processes comprising the network; and (2) checkpoint-specific master regulators monitor and govern the functional states of these processes. 相似文献
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48.
Two cellular factors have been described, Rab3A-GAP (GTPase-activating protein) and Rab3A-GRF (guanine nucleotide releasing factor) which, respectively, accelerate the intrinsic GTPase activity of, or the rate of dissociation of GDP from, the Ras-related GTP-binding protein, p25 Rab3A. Mutational analysis of p25 Rab3A was undertaken to define amino acid residues important for interaction with these factors. Mutations in residues 51-59, which correspond to the effector domain of p21 Ras, completely abolished sensitivity of p25 Rab3A to Rab3A-GRF and decreased the affinity of p25 Rab3A for Rab3A-GRF. Surprisingly, only one mutant in this region was Rab3A-GAP-insensitive, while the others retained partial, complete, or significantly increased GAP responsiveness. Mutations in the first G-domain had only modest effects on intrinsic GTPase activity and little effect on either Rab3A-GRF or Rab3A-GAP interactions. Truncation of 34 residues from the carboxyl terminus had no effect Rab3A-GAP sensitivity but facilitated Rab3A-GRF stimulation. Mutation T36N, analogous to the dominant inhibitory mutation T17N in Ras, which has been hypothesized to sequester an upstream activator of Ras, conferred a 10-fold higher affinity upon p25 Rab3A for Rab3A-GRF. 相似文献
49.
Bo Tan David K. O'Dell Y. William Yu M. Francesca Monn H. Velocity Hughes Sumner Burstein J. Michael Walker 《Journal of lipid research》2010,51(1):112-119
Using a partially purified bovine brain extract, our lab identified three novel endogenous acyl amino acids in mammalian tissues. The presence of numerous amino acids in the body and their ability to form amides with several saturated and unsaturated fatty acids indicated the potential existence of a large number of heretofore unidentified acyl amino acids. Reports of several additional acyl amino acids that activate G-protein coupled receptors (e.g., N-arachidonoyl glycine, N-arachidonoyl serine) and transient receptor potential channels (e.g., N-arachidonoyl dopamine, N-acyl taurines) suggested that some or many novel acyl amino acids could serve as signaling molecules. Here, we used a targeted lipidomics approach including specific enrichment steps, nano-LC/MS/MS, high-throughput screening of the datasets with a potent search algorithm based on fragment ion analysis, and quantification using the multiple reaction monitoring mode in Analyst software to measure the biological levels of acyl amino acids in rat brain. We successfully identified 50 novel endogenous acyl amino acids present at 0.2 to 69 pmol g−1 wet rat brain. 相似文献
50.
Cystic benign lymphoepithelial lesion (BLL), a previously rare lesion of the parotid gland consisting of marked lymphoid hyperplasia with accompanying squamous-lined cysts, has recently been described in patients with the acquired immune deficiency syndrome (AIDS) or AIDS risk factors. Thirteen fine needle aspiration (FNA) samples of parotid gland masses from patients with AIDS (one case), AIDS risk factors (five cases) or denial of AIDS risk factors (two cases) and a histopathologic diagnosis of BLL were examined. The FNA features that correlated best with the histopathologic findings were (1) a heterogeneous lymphoid population, (2) scattered single and/or clustered foamy macrophages and (3) superficial and/or anucleated squamous cells. Most aspirates showed some combination of these three components. The differential diagnostic considerations, the clinical and radiologic correlations and the relationship of this lesion to HIV infection are discussed. Patients with parotid masses whose aspirates consist of some combination of squamous cells, lymphocytes and foamy macrophages should be questioned for possible AIDS risk factors. 相似文献