-
MacPherson Espensen opublikował 5 miesięcy, 1 tydzień temu
Taken together, these findings suggest that Kras engages in cross talk with the Wnt/β-catenin pathway upon DMSO treatment of HL-60 cells, thereby regulating the granulocytic differentiation of HL-60 cells. These results indicate that Kras acts as a tumor suppressor during the differentiation of myeloid cells. © 2019 The Authors.Oocyte spindle transfer (OST) is a potent reproductive technology used for mammals that enables the spindle in a deteriorated oocyte at the metaphase of the second meiotic division (MII) to serve as the genetic material for producing descendants. However, whether postnatal growth is achieved via OST using developmentally deteriorated MII oocytes remains unclear. At 16 h after human chorionic gonadotropin administration, denuded MII oocytes immediately after retrieval from oviducts (0 h-oocytes) were used for in vitro fertilization (IVF) as controls. For IVF using postovulatory-aged oocytes, the 0 h-oocytes were further incubated for 12 h and 24 h (12 h- and 24 h-oocytes). These mouse oocytes served as a model for assessing the postnatal growth of individuals produced via OST from developmentally deteriorated oocytes. The embryos from 12 h- and 24 h-oocyte spindles exhibited high rates of development up to the neonatal stage as good as the non-manipulated controls. However, the mice derived from the 24 h-oocyte spindles displayed heavier body weights and greater feed consumption than both controls and mice derived from 12 h-oocyte spindles. Our results demonstrate the feasibility of OST as a potent reproductive technology and its limitation in the use of excessively aged postovulatory oocytes in mammalian reproduction. © 2019 The Authors.Diabetic kidney disease (DKD) is a life-limiting condition characterized by progressive and irreversible loss of renal function. Currently, the estimated glomerular filtration rate (eGFR) and albuminuria are used as key markers to define DKD. However, they may not accurately indicate the degree of renal dysfunction and injury. Current therapeutic approaches for DKD, including attainment of blood pressure goals, optimal control of blood glucose and lipid levels, and the use of agents to block the renin-angiotensin-aldosterone system (RAAS) can only slow the progression of DKD. Hence, early diagnosis and innovative strategies are needed to both prevent and treat DKD. In recent years, a novel class of noncoding RNA, microRNAs (miRNAs) are reported to be involved in all biological processes, including cellular proliferation, apoptosis, and differentiation. miRNAs are small noncoding RNAs that regulate gene expression by posttranscriptional and epigenetic mechanisms. They are found to be in virtually all body fluids and used successfully as biomarkers for various diseases. Urinary miRNAs correlate with clinical and histologic parameters in DKD and differential urinary miRNA expression patterns have been reported. Kidney fibrosis is the common end stage of various CKD including DKD. Transforming growth factor-β(TGF-β) is regarded as the master regulator of kidney fibrosis, which is likely at least in part through regulating miRNA expression. miRNA are widely involved in the progression of DKD via many molecular mechanisms. In this review, the involvement of miRNA in fibrosis, inflammation, hypertrophy, autophagy, endoplasmic reticulum (ER) stress, oxidative stress, insulin resistance, and podocyte injury will be discussed, as these mechanisms are believed to offer new therapeutic targets that can be exploited to develop important treatments for DKD over the next decade. © 2019 The Authors.A variety of internal and external factors such as exercise, nutrition, inflammation, and cancer-associated cachexia affect the regulation of skeletal muscle mass. Because skeletal muscle functions as a crucial regulator of whole body metabolism, rather than just as a motor for locomotion, the enhancement and maintenance of muscle mass and function are required to maintain health and reduce the morbidity and mortality associated with diseases involving muscle wasting. Recent studies in this field have made tremendous progress; therefore, identification of the mechanisms that regulate skeletal muscle mass is necessary for the physical and nutritional management of both athletes and patients with muscle wasting disease. In this review, we present an overall picture of the interactions regulating skeletal muscle mass, particularly focusing on the insulin-like growth factor-I (IGF-I)/insulin-Akt-mammalian target of rapamycin (mTOR) pathway, skeletal muscle inactivity, and endurance and resistance exercise. We also discuss the contribution of nitric oxide (NO) to the regulation of skeletal muscle mass based on the current knowledge of the novel role of NO in these processes. © 2019 The Authors.Mosaic loss of Y chromosome (LOY) is assumed to be among the most common acquired genetic variations in elderly people. Recent studies have linked aging-related mosaic LOY to the risk of Alzheimer’s disease, cancer, and early death. Here, we propose that mosaic LOY can present in men at any age. Mosaic LOY appears to be associated with disorders of sex development and Turner syndrome at birth, short stature from childhood, and spermatogenic failure at reproductive age, in addition to shortened survival after 60 years of age. © 2019 The Authors.Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease. Approximately 30% of patients do not respond to therapy with ursodeoxycholic acid (UDCA). Previous studies have implicated increased senescence of cholangiocytes in patients who do not respond to UDCA. This may increase the release of cytokines which drive pathogenic T cell polarization. As FXR agonists are beneficial in treating UDCA non-responsive patients, the current study was designed to model the interactions between cholangiocytes and CD4+ T cells to investigate potential immunomodulatory mechanisms of bile acid receptor agonists. Human cholangiocytes were co-cultured with CD4+ T cells to model the biliary stress response. Senescent cholangiocytes were able to polarize T cells toward a Th17 phenotype and suppressed expression of FoxP3 (P = 0.0043). Whilst FXR and TGR5 receptor agonists were unable directly to alter cholangiocyte cytokine expression, FGF19 was capable of significantly reducing IL-6 release (P = 0.044). Bile acid receptor expression was assessed in PBC patients with well-characterized responsiveness to UDCA therapy. A reduction in FXR staining was observed in both cholangiocytes and hepatocytes in PBC patients without adequate response to UDCA. Increased IL-6 expression by senescent cholangiocytes represents a potential mechanism by which biliary damage in PBC could contribute to excessive inflammation. © 2019 The Authors.Cytokinins (CKs) encompass a group of phytohormones, known to orchestrate many critical processes in plant development. Excluding Archaea, CKs are pervasive among all kingdoms, but much less is reported about their metabolism beyond plants. Recent evidence from mammalian tissues indicates the presence of six additional CK forms beyond the previously identified, single mammalian CK, N6-isopentenyladenosine (i6A). There is limited understanding of CK biosynthesis pathways in mammalian systems; therefore, human cervical cancer (HeLa) cells were used to further characterize CK processing by tracking the interconversion of CKs into their various structural derivatives in mammalian cells in a time-course study. Through high-performance liquid chromatography-positive electrospray ionization-tandem mass spectrometry (HPLC-(+ESI)-MS/MS), we document changes in the functional profiles of endogenous CKs in a human cell line following metabolism by HeLa cell cultures. The nucleotide CK fraction (iPRP) was found exclusively within the cell pellet (0.34 pmol/106 cells), and the active free base (FB) form (iP) and riboside fraction (iPR) were found in greater abundance extracellularly (1.67 and 0.10 nmol/L respectively). For further confirmation, we demonstrate that HeLa cells metabolize an exogenously supplied CK, N6-benzyladenosine (BAR). In the HeLa culture supernatant, a 12-fold decrease in BAR concentration was observed within the first 24 hours of incubation accompanied by a fivefold increase in the FB form, N6-benzyladenine (BA). These findings support the hypothesis that HeLa cells have the enzymatic pathways required for the metabolism of both endogenous and exogenous CKs. © 2019 The Authors.The analysis of whole genomes has revealed specific geographical distribution of Mycobacterium tuberculosis (Mtb) strains across the globe suggestive of unique niche dependent adaptive mechanisms. We provide an important correlation of a genome-based mutation to a molecular phenotype across two predominant clinical Mtb lineages of the Indian subcontinent. We have identified a distinct lineage specific mutation-G247C, translating into an alanine-proline conversion in the papA2 gene of Indo-oceanic lineage 1 (L1) Mtb strains, and restoration of cell wall sulfolipids by simple genetic complementation of papA2 from lineage 3 (L3) or from H37Rv (lineage 4-L4) attributed the loss of this glycolipid to this specific mutation in Indo-Oceanic L1 Mtb. The investigation of structure of Mtb PapA2 revealed a distinct nonribosomal peptide synthetase (NRPS) C domain conformation with an unconventional presence of a zinc binding motif. Surprisingly, the A83P mutation did not map to either the catalytic center in the N-termincular consequence in Mtb highlighting one of the many adaptive mechanisms that have contributed to its success as a human pathogen. A high degree of identity with PapA1, 3, or 4 would help in interpreting the structure of these PapA proteins and other acyl transferases of other biological systems. © 2019 The Authors.During aging, glutathione (GSH) content declines and the immune system undergoes a deficiency in the induction of Th1 response. Reduced secretion of Th1 cytokines, which is associated with GSH depletion, could weaken the host defenses against viral infections. We first evaluated the concentration of GSH and cysteine in organs of old mice; then, the effect of the administration of the N-butanoyl GSH derivative (GSH-C4) on the response of aged mice infected with influenza A PR8/H1N1 virus was studied through the determination of GSH concentration in organs, lung viral titer, IgA and IgG1/IgG2a production, and Th1/Th2 cytokine profile. Old mice had lower GSH than young mice in organs. Also the gene expression of endoplasmic reticulum (ER) stress markers involved in GSH metabolism and folding of proteins, that is, Nrf2 and PDI, was reduced. Following infection, GSH content remained low and neither infection nor GSH-C4 treatment affected Nrf2 expression. In contrast, PDI expression was upregulated during infection and appeared counterbalanced by GSH-C4. Moreover, the treatment with GSH-C4 increased GSH content in organs, reduced viral replication and induced a predominant Th1 response. In conclusion, GSH-C4 treatment could be used in the elderly to contrast influenza virus infection by inducing immune response, in particular the Th1 profile. © 2019 The Authors.