Stimulation of fatty acid synthesis in vitro by gonadotrophin-induced testicular ribonucleic acid.
Ontology highlight
ABSTRACT:
SUBMITTER: Goswami A
PROVIDER: S-EPMC1198780 | biostudies-other | 1968 Jun
REPOSITORIES: biostudies-other
Similar Datasets
Project description:The future fertility of prepubertal boys with cancer may be irreversibly compromised by chemotherapy and/or radiotherapy. Successful spermatogenesis has not been achieved following the xenotransplantation of prepubertal human testis tissue, which is likely due to the failure of somatic cell maturation and function. We used a validated xenograft model to identify the factors required for Leydig and Sertoli cell development and function in immature human testis. Importantly, we compared the maturation status of Sertoli cells in xenografts with that of human testis tissues (n = 9, 1 year-adult). Human fetal testis (n = 6; 14-21 gestational weeks) tissue, which models many aspects of prepubertal testicular development, was transplanted subcutaneously into castrated immunocompromised mice for ~12 months. The mice received exogenous human chorionic gonadotropin (hCG; 20IU, 3×/week). In xenografts exposed continuously to hCG, we demonstrate the maintenance of Leydig cell steroidogenesis, the acquisition of features of Sertoli cell maturation (androgen receptor, lumen development), and the formation of the blood-testis barrier (connexin 43), none of which were present prior to the transplantation or in xenografts in which hCG was withdrawn after 7 months. These studies provide evidence that hCG plays a role in Sertoli cell maturation, which is relevant for future investigations, helping them generate functional gametes from immature testis tissue for clinical application.
| S-EPMC7019512 | biostudies-literature
Project description:1. The incorporation of [2-(14)C]uridine into nucleic acids of bone cells was studied in rat and pig trabecular-bone fragments surviving in vitro. 2. The rapid uptake of uridine into trichloroacetic acid-soluble material, and its subsequent incorporation into a crude nucleic acid fraction of bone or purified RNA extracted from isolated bone cells, was proportional to uridine concentration in the incubation medium over a range 0.5-20.0mum. 3. During continued exposure to radioactive uridine, bulk RNA became labelled in a curvilinear fashion. Radioactivity rapidly entered nuclear RNA, which approached its maximum specific activity by 2hr. of incubation; cytoplasmic RNA, and particularly microsomal RNA, was more slowly labelled. The kinetics of labelling and rapid decline of the nuclear/microsomal specific activity ratio were consistent with a precursor-product relationship. 4. Bulk RNA preparations were resolved by zonal centrifugation in sucrose density gradients into components with approximate sedimentation coefficients 28s, 18s and 4s. 5. Rapidly labelled RNA, predominantly nuclear in location, demonstrated a polydisperse sedimentation pattern that did not conform to the major types of stable cellular RNA. Material of highest specific activity, sedimenting in the 4-18s region and insoluble in 10% (w/v) sodium chloride, rapidly achieved its maximum activity during continued exposure to radioactive precursor and decayed equally rapidly during ;chase' incubation, exhibiting an average half-life of 4.3hr. 6. Ribosomal 28s and 18s RNA were of lower specific activity, which increased linearly for at least 6hr. in the continued presence of radioactive uridine. There was persistent but variable incorporation into ribosomal RNA during ;chase' incubation despite rapid decline in total radioactivity of the acid-soluble pool containing RNA precursors.
| S-EPMC1198386 | biostudies-other
Project description:Metabolic diseases are closely linked to aberrant synthesis of endogenous fatty acids in the liver, called de novo lipogenesis (DNL), which is mediated by the enzyme fatty acid synthase (FASN). The composition of complex lipids consists of saturated or monosaturated fatty acids, which can be endogenously produced, and polyunsaturated fatty acids (PUFA), which are strictly dietary. Compositional differences between individuals are insufficiently understood and may influence the onset and progression of metabolic and cardiovascular diseases. Here we show that DNL critically determines the use of dietary PUFA. A patient with a hypofunctional heterozygous de novo Arg2177Cys variant in FASN exhibited an elevated composition of PUFA, which was phenocopied by pharmacological inhibition of FASN with TVB-2640 in patients with nonalcoholic steatohepatitis (NASH). In mice, the incorporation rate of supplemented omega-3 PUFA during an obesogenic diet was increased by genetic or pharmacologic reduction of DNL. Mechanistically, we show that the FASN variant exhibited a cysteine-dependent, non-enzymatic acetylation of FASN, which resulted in hyperubiquitinylation and decreased protein stability. Our study further reveals that PUFA storage is an active, enzymatic process controlled by FASN, diacylglycerol O-acyltransferase 2 (DGAT2) and MFSD2A, a membrane-transport protein, and that combining FASN inhibition and PUFA supplementation exerts additive beneficial metabolic effects. These findings provide evidence that the success of PUFA supplementation may depend on the rate of endogenous DNL and that combined PUFA supplementation and FASN inhibition may be a promising approach targeting metabolic disease.
2023-12-19 | PXD045908 | Pride
Project description:The purpose of this study was to determine the role of the proinflammatory cytokine interleukin (IL) 6 in cold-induced hypertension. Four groups of male Sprague-Dawley rats were used (6 rats per group). After blood pressure was stabilized, 3 groups received intravenous delivery of adenoassociated virus carrying IL-6 small hairpin RNA (shRNA), adenoassociated virus carrying scrambled shRNA, and PBS, respectively, before exposure to a cold environment (5 degrees C). The last group received PBS and was kept at room temperature (25 degrees C, warm) as a control. Adenoassociated virus delivery of IL-6 shRNA significantly attenuated cold-induced elevation of systolic blood pressure and kept it at the control level for < or =7 weeks (length of the study). Chronic exposure to cold upregulated IL-6 expression in aorta, heart, and kidneys and increased macrophage and T-cell infiltration in kidneys, suggesting that cold exposure increases inflammation. IL-6 shRNA delivery abolished the cold-induced upregulation of IL-6, indicating effective silence of IL-6. Interestingly, RNA interference knockdown of IL-6 prevented cold-induced inflammation, as evidenced by a complete inhibition of tumor necrosis factor-alpha expression and leukocyte infiltration by IL-6 shRNA. RNA interference knockdown of IL-6 significantly decreased the cold-induced increase in vascular superoxide production. It is noted that IL-6 shRNA abolished the cold-induced increase in collagen deposition in the heart, suggesting that inflammation is involved in cold-induced cardiac remodeling. Cold exposure caused glomerular collapses, which could be prevented by knockdown of IL-6, suggesting an important role of inflammation in cold-induced renal damage. In conclusion, cold exposure increased IL-6 expression and inflammation, which play critical roles in the pathogenesis of cold-induced hypertension and cardiac and renal damage.
| S-EPMC2894564 | biostudies-literature
Project description:A system has been developed which allows the stimulation in vitro of prostatic RNA polymerase by prostatic 5alpha-dihydrotestosterone-protein receptor complexes prepared from the tissues of castrated rats. The reconstitution in vitro of such a system necessitates the purification of several subcellular components. Two 5alpha-dihydrotestosterone-receptor complexes are located in the prostatic soluble supernatant fraction, separable by selective ammonium sulphate fractionation, and one complex can be isolated from the nuclear fraction. In the presence of all these complexes, stimulation of RNA polymerase in intact nuclei and nucleoli was observed. The complexes also increased the activity of the enzyme solubilized from whole nuclei. Greater stimulation of this system was noted in the presence of prostatic chromatin as template, as compared with that observed with calf thymus DNA or liver chromatin as template. The effects of the complexes on subnuclear forms of RNA polymerase, of nucleolar and extranucleolar origin, are also described. RNA polymerase solubilized from nucleoli is more susceptible to stimulation by the 5alpha-dihydrotestosterone-receptor complexes than is the ;nucleoplasmic' enzyme. Stimulation occurs less readily in the presence of Mn(2+) and at high ionic strength than in the presence of Mg(2+) and at low ionic strength. Preliminary experiments show that prostatic nucleolar RNA polymerase transcribes prostatic chromatin poorly as compared with the nucleoplasmic enzyme. The observations reported indicate an involvement of non-histone proteins associated with DNA in the process by which stimulation of enzyme activity by the 5alpha-dihydrotestosterone-receptor complexes is achieved. The implications of these findings in the mechanism of steroid hormone action is considered.
| S-EPMC1165996 | biostudies-other
Project description:Cells harbor two systems for the synthesis of fatty acids, one in the cytoplasm (FASN or fatty acid synthase) and one in the mitochondria (mtFAS). In contrast to FASN, mtFAS is poorly characterized, with the major product(s), metabolic roles, and cellular function(s) essentially unknown. Here we show that hypomorphic mtFAS mutants display a profound loss of electron transport chain (ETC) complexes and exhibit compensatory reductive carboxylation. This effect on ETC complexes is independent of the synthesis of lipoic acid, the best characterized function of mtFAS, as mutants lacking lipoic acid synthesis have an intact ETC. Finally, mtFAS impairment blocks the differentiation of skeletal myoblasts in vitro. These data suggest that ETC activity in mammals is profoundly controlled by mtFAS function, thereby connecting anabolic fatty acid synthesis with the oxidation of carbon fuels.
2020-08-17 | GSE148617 | GEO
Project description:The incorporation of [(3)H]uridine into RNA was studied quantitatively (by incorporation of [(3)H]uridine into acid-precipitable material) and qualitatively (by phenol extraction and electrophoretic separation of RNA in polyacrylamide gels) in preparations enriched in primary spermatocytes, obtained from testes of rats 26 or 32 days old. The rate of incorporation of [(3)H]uridine into RNA of isolated spermatocytes was constant during the first 8h of incubation, after which it decreased, but the decreased rate of incorporation was not reflected in a marked change in electrophoretic profiles of labelled RNA. In isolated spermatocytes, [(3)H]uridine was incorporated mainly into heterogeneous RNA with a low electrophoretic mobility. Most of this RNA was labile, as shown when further RNA synthesis was inhibited with actinomycin D. Spermatocytes in vivo also synthesized heterogeneous RNA with a low electrophoretic mobility. A low rate of incorporation of [(3)H]uridine into rRNA of isolated spermatocytes was observed. The cleavage of 32S precursor rRNA to 28S rRNA was probably retarded in spermatocytes in vitro as well as in vivo. RNA synthesis by preparations enriched in early spermatids or Sertoli cells was qualitatatively different from RNA synthesis by the spermatocyte preparations. It is concluded that isolated primary spermatocytes maintain a specific pattern of RNA synthesis, which resembles RNA synthesis in spermatocytes in vivo. Therefore isolated spermatocytes of the rat can be used for studying the possible regulation of RNA synthesis during the meiotic prophase.
| S-EPMC1184113 | biostudies-other
Project description:Non-alcoholic fatty liver disease (NAFLD), ranging from simple steatosis to non-alcoholic steatohepatitis (NASH), hepatic fibrosis and even hepatocellular carcinoma, is a liver disease worldwide without approved therapeutic drugs. Baicalein (BAL), a flavonoid compound extracted from the Traditional Chinese Medicine (TCM) Scutellariae Radix (Scutellaria baicalensis Georgi.), has been used in TCM clinical practice for thousands of years to treat liver diseases due to its "hepatoprotective effect". However, the underlying liver-protecting mechanisms remain largely unknown. Here, we found that oral administration of BAL significantly decreased excess serum levels of triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), aspartate aminotransferase (AST) as well as hepatic TG in fructose-fed rats. Attenuation of the increased vacuolization and Oil Red O staining area was evident on hepatic histological examination in BAL-treated rats. Mechanistically, results of RNA-sequencing, western-blot, real-time quantitative PCR (RT-qPCR) and hepatic metabolomics analyses indicated that BAL decreased fructose-induced excessive nuclear expressions of mature sterol regulatory element-binding protein 1c (mSREBP1c) and carbohydrate response element-binding protein (ChREBP), which led to the decline of lipogenic molecules [including fatty acid synthase (FASN), stearoyl-CoA desaturase 1 (SCD1), elongation of very long chain fatty acids 6 (ELOVL6), acetyl-CoA carboxylase (ACC)], accompanying with the alternation of hepatic fatty acids composition. Meanwhile, BAL enhanced fatty acid oxidation by activating AMPK/PGC1α signaling axis and PPARα signal pathway, which elicited high expression of carnitine palmitoyl transferase 1α (CPT1α) and Acyl-CoA oxidase 1 (ACO1) in livers of fructose-fed rats, respectively. BAL ameliorated fructose-induced hepatic steatosis, which is associated with regulating fatty acid synthesis, elongation and oxidation.
| S-EPMC9280198 | biostudies-literature
Project description:Noncoding RNA (ncRNA) is a kind of RNA that plays an important role in many biological processes, diseases, and cancers, while cannot translate into proteins. With the development of next-generation sequence technology, thousands of novel RNAs with long open reading frames (ORFs, longest ORF length > 303 nt) and short ORFs (longest ORF length ? 303 nt) have been discovered in a short time. How to identify ncRNAs more precisely from novel unannotated RNAs is an important step for RNA functional analysis, RNA regulation, etc. However, most previous methods only utilize the information of sequence features. Meanwhile, most of them have focused on long-ORF RNA sequences, but not adapted to short-ORF RNA sequences. In this paper, we propose a new reliable method called NCResNet. NCResNet employs 57 hybrid features of four categories as inputs, including sequence, protein, RNA structure, and RNA physicochemical properties, and introduces feature enhancement and deep feature learning policies in a neural net model to adapt to this problem. The experiments on benchmark datasets of 8 species shows NCResNet has higher accuracy and higher Matthews correlation coefficient (MCC) compared with other state-of-the-art methods. Particularly, on four short-ORF RNA sequence datasets, specifically mouse, Saccharomyces cerevisiae, zebrafish, and cow, NCResNet achieves greater than 10 and 15% improvements over other state-of-the-art methods in terms of accuracy and MCC. Meanwhile, for long-ORF RNA sequence datasets, NCResNet also has better accuracy and MCC than other state-of-the-art methods on most test datasets. Codes and data are available at https://github.com/abcair/NCResNet.
| S-EPMC7059790 | biostudies-literature
Project description:Macrophages exhibit a spectrum of activation states ranging from classical to alternative activation1. Alternatively activated macrophages are involved in diverse pathophysiological processes such as confining tissue parasites2, improving insulin sensitivity3 or promoting an immune tolerant microenvironment that facilitates tumour growth and metastasis4. Recently, the role of metabolism in the regulation of macrophage function has come into focus as both the classical and alternative activation programmes require specific regulated metabolic reprogramming5. While most of the studies regarding immunometabolism have focussed on the catabolic pathways activated to provide energy, little is known about the anabolic pathways mediating macrophage alternative activation. In this study, we show that the anabolic transcription factor sterol regulatory element binding protein 1 (SREBP1) is activated in response to the canonical Th2 cytokine interleukin 4 (IL-4) to trigger the de novo lipogenesis (DNL) programme, as a necessary step for macrophage alternative activation. Mechanistically, DNL consumes NADPH, partitioning it away from cellular antioxidant defences and raising ROS levels. ROS serves as a second messenger, signalling sufficient DNL, and promoting macrophage alternative activation. The pathophysiological relevance of this mechanism is validated by showing that SREBP1/DNL is essential for macrophage alternative activation in vivo in a helminth infection model.
2021-07-30 | GSE179066 | GEO