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1.
P C Andrews H G Pollock W M Elliott J H Youson E M Plisetskaya 《The Journal of biological chemistry》1988,263(30):15809-15814
Three major forms of somatostatin were isolated from pancreas of the lamprey (Petromyzon marinus). One of the two major forms is a 14-residue somatostatin (SS-14) having the sequence AGCKNFFWKTFSSC. The homologous substitution Ser for Thr in position 12 is the first example of SS-14 from vertebrate preprosomatostatin gene I having a divergent sequence. The longest form is 37 residues in length (SS-37) and has the sequence ALRAAAVAGSPQQLLPLGQRERKAGCKNFFWKTFSSC. A 34-residue form (SS-34) identical in sequence but truncated at a single Arg residue at position 3 of SS-37 was also isolated. The yields of the three forms were SS-37 (0.43 nmol/g), SS-34 (134 nmol/g), and SS-14 (51.5 nmol/g). The identification of this nested series of somatostatins suggests that prosomatostatin processing in lamprey more closely resembles that observed for procholecystokinin than that of mammalian or other piscine prosomatostatins. Somatostatin-producing cells in the lamprey pancreas were identified by immunostaining using antiserum against SS-34 and anti-serum against mammalian SS-14. 相似文献
2.
The effects of exogenous administration of gonadotropin-releasing hormone (GnRH) analogues or of a partly purified salmon gonadotropin extract (GTH) on the duration of steroid and thyroid hormone levels were determined in female and male sea lampreys, Petromyzon marinus, tested under differing temperature and reproductive status. Plasma estradiol levels, but not androgens, were significantly elevated in response to the GnRH analogues or GTH injection compared to controls in female and male lampreys. Higher temperature and/or advance in time of maturation appeared to be inversely related to plasma estradiol levels. These data provide further evidence of hypothalamic control over reproductive function in lampreys. Plasma thyroxine was significantly elevated after female lampreys were treated with GTH, GnRHa (10 micrograms/lamprey) or GnRHa (1 microgram/lamprey) compared to controls. The present study is the first to demonstrate that the GnRH analogue stimulated in some way the pituitary-thyroid axis. These data suggest that a GnRH activity may activate both gonado- and thyrotropic secretion or that the endogenous hormone may itself have both functions in one of the most primitive vertebrates, the sea lamprey. 相似文献
3.
Thyroid hormones in cyclostomes and fish and their role in regulation of intermediary metabolism 总被引:2,自引:0,他引:2
E Plisetskaya N Y Woo J C Murat 《Comparative biochemistry and physiology. A, Comparative physiology》1983,74(2):179-187
1. Experimental data obtained in cyclostomes and fish concerning the plasma levels of thyroxine and tri-iodothyronine as well as their influence on intermediary metabolism of lipids, carbohydrates, and proteins are reviewed. 2. The information dealing with the physiological role of thyroid hormones in regulation of metabolic processes seems to be scarce in cyclostomes and controversial in fishes. 3. Nevertheless, the data covered in the review support the generalization that thyroid hormones, probably along with some other hormones, exert a regulatory action on the metabolic processes already on the lower stage of the evolution of poikilothermic vertebrates. 相似文献
4.
Metabolic changes in coho and chinook salmon resulting from acute insufficiency in pancreatic hormones 总被引:1,自引:0,他引:1
Acute deficiency in pancreatic peptides (insulin, somatostatin-25, glucagon, and glucagon-like peptide) was invoked for 9-12 hr in coho, Oncorhynchus kisutch, and chinook, O. tshawytscha, salmon by administration of specific antisera raised against purified salmon hormones. Insulin-deficient fish were hyperglycemic, had diminished glycogen content in the liver (Plisetskaya et al., '88a, elevated liver triacylglycerol lipase activity, and higher concentration of plasma triiodothyronine (T3) compared to a control group of fish injected with nonspecific rabbit serum. After immunoneutralization of somatostatin-25, fish remained normoglycemic, with higher liver glycogen content, decreased lipase activity, and elevated plasma levels of insulin, while the levels of T3 declined. The induced deficiency in glucagon family peptides led to comparatively smaller changes: liver glycogen content was increased after anti-glucagon-like peptide (aGLP) injection and transient hyperglycemia was apparent following anti-glucagon (aGLU) administration. Circulating levels of insulin remained unaffected for at least 9 hr following aGLU and aGLP treatments. The velocity of pyruvate kinase at 2.5 mM phosphoenolpyruvate (V2.5) was depressed, especially after the combined administration of aGLU + aGLP. The effectiveness of immunoneutralization experiments was greatly dependent on the particular stage of the fish life cycle. Antisera against fish pancreatic peptides proved to be a suitable tool in the studies of hormonal regulation of fish metabolism. 相似文献
5.
6.
Jessica AB van Nies Rute B Marques Stella Trompet Zuzana de Jong Fina AS Kurreeman Rene EM Toes J Wouter Jukema Tom WJ Huizinga Annette HM van der Helm-van Mil 《Arthritis research & therapy》2010,12(2):R38
Introduction
Recently an association between a genetic variation in TRAF1/C5 and mortality from sepsis or cancer was found in rheumatoid arthritis (RA). The most prevalent cause of death, cardiovascular disease, may have been missed in that study, since patients were enrolled at an advanced disease stage. Therefore, we used an inception cohort of RA patients to investigate the association between TRAF1/C5 and cardiovascular mortality, and replicate the findings on all-cause mortality. As TRAF1/C5 associated mortality may not be restricted to RA, we also studied a large cohort of non-RA patients. 相似文献7.
Intervention with mesenchymal stem cells (MSCs) represents a promising therapeutic tool in treatment-refractory autoimmune
diseases. A new report by Schurgers and colleagues in a previous issue of Arthritis Research & Therapy sheds novel mechanistic insight into the pathways employed by MSCs to suppress T-cell proliferation in vitro, but, at the same time, indicates that MSCs do not influence T-cell reactivity and the disease course in an in vivo arthritis model. Such discrepancies between the in vitro and in vivo effects of potent cellular immune modulators should spark further research and should be interpreted as a sign of caution
for the in vitro design of MSC-derived interventions in the setting of human autoimmune diseases. 相似文献
8.
Bahareh Honarparvar Sachin A Pawar Cláudio Nahum Alves Jer?nimo Lameira Glenn EM Maguire José Rogério A Silva Thavendran Govender Hendrik G Kruger 《Journal of biomedical science》2015,22(1)
Background
Novel pentacycloundecane (PCU)-lactone-CO-EAIS peptide inhibitors were designed, synthesized, and evaluated against wild-type C-South African (C-SA) HIV-1 protease. Three compounds are reported herein, two of which displayed IC50 values of less than 1.00 μM. A comparative MM-PB(GB)SA binding free energy of solvation values of PCU-lactam and lactone models and their enantiomers as well as the PCU-lactam-NH-EAIS and lactone-CO-EAIS peptide inhibitors and their corresponding diastereomers complexed with South African HIV protease (C-SA) was performed. This will enable us to rationalize the considerable difference between inhibitory concentration (IC50) of PCU-lactam-NH-EAIS and PCU-lactone-CO-EAIS peptides.Results
The PCU-lactam model exhibited more negative calculated binding free energies of solvation than the PCU-lactone model. The same trend was observed for the PCU-peptide inhibitors, which correspond to the experimental activities for the PCU-lactam-NH-EAIS peptide (IC50 = 0.076 μM) and the PCU-lactone-CO-EAIS peptide inhibitors (IC50 = 0.850 μM). Furthermore, a density functional theory (DFT) study on the natural atomic charges of the nitrogen and oxygen atoms of the three PCU-lactam, PCU-lactim and PCU-lactone models were performed using natural bond orbital (NBO) analysis. Electrostatic potential maps were also used to visualize the electron density around electron-rich regions. The asymmetry parameter (η) and quadrupole coupling constant (χ) values of the nitrogen and oxygen nuclei of the model compounds were calculated at the same level of theory. Electronic molecular properties including polarizability and electric dipole moments were also calculated and compared. The Gibbs theoretical free solvation energies of solvation (∆Gsolv) were also considered.Conclusions
A general trend is observed that the lactam species appears to have a larger negative charge distribution around the heteroatoms, larger quadrupole constant, dipole moment and better solvation energy, in comparison to the PCU-lactone model. It can be argued that these characteristics will ensure better eletronic interaction between the lactam and the receptor, corresponding to the observed HIV protease activities in terms of experimental IC50 data.Electronic supplementary material
The online version of this article (doi:10.1186/s12929-015-0115-5) contains supplementary material, which is available to authorized users. 相似文献9.
Nadine Kraemer Ethiraj Ravindran Sami Zaqout Gerda Neubert Detlev Schindler Olaf Ninnemann Ralph Gr?f Andrea EM Seiler Angela M Kaindl 《Cell cycle (Georgetown, Tex.)》2015,14(13):2044-2057
Biallelic mutations in the gene encoding centrosomal CDK5RAP2 lead to autosomal recessive primary microcephaly (MCPH), a disorder characterized by pronounced reduction in volume of otherwise architectonical normal brains and intellectual deficit. The current model for the microcephaly phenotype in MCPH invokes a premature shift from symmetric to asymmetric neural progenitor-cell divisions with a subsequent depletion of the progenitor pool. The isolated neural phenotype, despite the ubiquitous expression of CDK5RAP2, and reports of progressive microcephaly in individual MCPH cases prompted us to investigate neural and non-neural differentiation of Cdk5rap2-depleted and control murine embryonic stem cells (mESC). We demonstrate an accumulating proliferation defect of neurally differentiating Cdk5rap2-depleted mESC and cell death of proliferative and early postmitotic cells. A similar effect does not occur in non-neural differentiation into beating cardiomyocytes, which is in line with the lack of non-central nervous system features in MCPH patients. Our data suggest that MCPH is not only caused by premature differentiation of progenitors, but also by reduced propagation and survival of neural progenitors. 相似文献
10.
Suurmond J Dorjée AL Boon MR Knol EF Huizinga TW Toes RE Schuerwegh AJ 《Arthritis research & therapy》2011,13(5):R150