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The mechanism of P2 repression by the TyrR protein in Escherichia coli has been investigated. Results demonstrate that TyrR protein inhibits open complex formation at P2 in the presence of tyrosine.

A study of in vitro transcription within the peripheral area of the aroP genetic coding region determined the presence of three promoters, P1, P2 and P3. Analyses of regulation of promoter activity were done in vitro through supercoiled DNA templates and in vivo through lacZ transcriptional fusions and specific promoter mutants. Results show that P3, which initiates transcription away from the aroP protein, is repressed by the TyrR regulon. P2 is partially repressed. P1 was not affected by TyrR. However, insertion mutation via roadblock k mechanism of the transcriptional start site of P1 inhibited production of truncated RNA molecules.

Abstract Background The ubiquitously expressed POU homeodomain protein Oct-1 serves as a sensor for stress induced by irradiation. We found recently that in pancreatic and intestinal endocrine cells, Oct-1 also functions as a sensor for cyclic AMP (cAMP). The caudal homeobox gene Cdx-2 is a transactivator of proglucagon (gcg) and pro-insulin genes. Oct-1 binds to Cdx-2 promoter and represses its expression. cAMP elevation leads to increased nuclear exclusion of Oct-1, associated with reduced recruitment of nuclear co-repressors to the Cdx-2 promoter and increased Cdx-2 expression. Results We show in this study that inducing oxidative stress by hydrogen peroxide (H2O2) increased nuclear Oct-1 content in both pancreatic α and β cell lines, as well as in a battery of other cells. This increase was then attributed to accelerated nuclear import of Oct-1, assessed by Fluorescence Recovery After Photobleaching (FRAP) using green fluorescence protein (EGFP) tagged Oct-1 molecule. H2O2 treatment was then shown to stimulate the activities of DNA-dependent protein kinase (DNA-PK) and c-jun N-terminal kinase (JNK). Finally, increased Oct-1 nuclear content upon H2O2 treatment in a pancreatic α cell line was associated with reduced Cdx-2 and gcg mRNA expression. Conclusion These observations suggest that Oct-1 functions as a sensor for both metabolic and stress/survival signaling pathways via altering its nuclear-cytoplasmic shuttling.

Mammalian glycogen chain lengths are subject to complex regulation, including by seven proteins (protein phosphatase‐1 regulatory subunit 3, PPP1R3A through PPP1R3G) that target protein phosphatase‐1 (PP1) to glycogen to activate the glycogen chain‐elongating enzyme glycogen synthase and inactivate the chain‐shortening glycogen phosphorylase. Lafora disease is a fatal neurodegenerative epilepsy caused by aggregates of long‐chained, and as a result insoluble, glycogen, termed Lafora bodies (LBs). We previously eliminated PPP1R3C from a Lafora disease mouse model and studied the effect on LB formation. In the present work, we eliminate and study the effect of absent PPP1R3D. In the interim, brain cell type levels of all PPP1R3 genes have been published, and brain cell type localization of LBs clarified. Integrating these data we find that PPP1R3C is the major isoform in most tissues including brain. In the brain, PPP1R3C is expressed at 15‐fold higher levels than PPP1R3D in astrocytes, the cell type where most LBs form. PPP1R3C deficiency eliminates ~90% of brain LBs. PPP1R3D is quantitatively a minor isoform, but possesses unique MAPK, CaMK2 and 14‐3‐3 binding domains and appears to have an important functional niche in murine neurons and cardiomyocytes. In neurons, it is expressed equally to PPP1R3C, and its deficiency eliminates ~50% of neuronal LBs. In heart, it is expressed at 25% of PPP1R3C where its deficiency eliminates ~90% of LBs. This work studies the role of a second (PPP1R3D) of seven PP1 subunits that regulate the structure of glycogen, toward better understanding of brain glycogen metabolism generally, and in Lafora disease. [ABSTRACT FROM AUTHOR]

Growth hormone secretagogue receptor 1α (GHSR1a) and Orexin 1 receptor (OX1R) are involved in various important physiological processes, and have many similar characteristics in function and distribution in peripheral tissues and the central nervous system. We explored the possibility of heterodimerization between GHSR1a and OX1R and revealed a signal transduction pathway mechanism. In this study, bioluminescence and fluorescence resonance energy transfer and co-immunoprecipitation (Co-IP) analyses were performed to demonstrate the formation of functional GHSR1a/OX1R heterodimers. This showed that a peptide corresponding to the 5-transmembrane domain of OX1R impaired heterodimer construction. We found that ghrelin stimulated GHSR1a/OX1R heterodimer cells to increase the activation of Gαs protein, compared to the cells that express GHSR1a. Stimulation of GHSR1a/OX1R heterodimers with orexin-A did not alter GPCR interactions with Gα protein subunits. GHSR1a/OX1R heterodimers induced Gαs and downstream signaling pathway activity, including increase of cAMP-response element luciferase reporter activity and cAMP levels. In addition, ghrelin induced a higher proliferation rate in SH-SY5Y cells than in controls. This suggests that ghrelin GHSR1a/OX1R heterodimers promotes an upregulation of a Gαs-cAMP-cAMP-responsive element signaling pathway in vitro and an increase in neuroblastoma cell proliferation. [ABSTRACT FROM AUTHOR]

Objective: To preliminarily develop a surfactant-free, polymeric solid dispersion (PSD) of paclitaxel suitable for oral administration. Methods: A co-solvent quench method was applied to screen the proper polymer matrix of the PSD which were prepared in a liquid system using a quasi-emulsion solvent diffusion method (QESDM). Three dissolution experiments and twoin vivotests in rats were used to explain the differences among the formulations. Results: The theoretical solubility ratio of amorphous/crystalline PTX was 92.6 (37 °C). Hydroxypropyl methylcellulose acetate succinate (HPMCAS) was chosen as the polymer carrier of the PSD and a porous silicon dioxide [called white carbon black (WCB)] was selectable to be used to further adjust the dissolution rate. The absolute oral bioavailability (AOB, 20 mg/kg) of the three formulas [HPMCAS/paclitaxel/WCB = 4/1/0 (F1), 8/1/0 (F2) and 4/1/4 (F3), w/w/w] were 11.8, 13.6 and 25.6%, respectively. The AOB of F3 is nearly seven times higher than that (3.8%) of paclitaxel material (a control). The advantage of higher HPMCAS/paclitaxel ratio of F2 in a dissolution test was not reflected in the firstin vivotest due to the relatively higher dose of polymer which could not be effectively dissolved under the limitation of intestinal environment. This was deduced from the dissolution tests and was finally validated when the oral dose of PTX (and thus polymer) was reduced. The relevant AOBs (10 mg/kg) were 10.4, 20.8 and 19.6%, respectively. Conclusion: The PSD is a promising formulation strategy and the QESDM is a practical preparation method to implement such formulation design. [ABSTRACT FROM AUTHOR]

Focuses on a study which looked at the repression of the aroP gene of Escherichia coli. Involvement of the activation of a divergent promoter in this process; Information on tyrosine-mediated repression; Results of the study; Discussion of these results.

Objective: To quantitatively and qualitatively evaluate research trends and hotspots for immune checkpoint inhibitors (ICIs), according to the most frequently cited clinical trials., Background: Numerous clinical trials have been carried out using ICIs for activating anti-tumor immunity in cancer patients. The most frequently cited clinical trials have been used as a database for achieving the objectives of this analysis., Materials and Methods: The most frequently cited articles on ICIs meeting the inclusion criteria were extracted from the Web of Science database. Citation report information including annual outputs, most relevant journals, and country of origin together with burst references, keywords, information on co-occurrence, citation networks, and cluster topics were analyzed using standard bibliometric procedures., Results: A total of 112 most frequently cited articles on clinical trials of ICIs were retrieved for the period 2013 to 2021 of which the journal JAMA Oncology had the highest number of citations. Most studies originated in the U.S., and therefore studies from this country had a determinant effect of the results of the investigation. Burst reference topics included studies on ipilimumab for melanoma, anti-PD-L1 antibody in advanced cancer, anti-PD-1 antibody in cancer, nivolumab combined with ipilimumab or as monotherapy in untreated melanoma, and pembrolizumab for PD-L1 positive non-small-cell lung cancer. Nine clusters were grouped in the citation network. The topic/keywords "cancer", "immunotherapy", "PD-1 blockade", "PD-L1", "expression", "ipilimumab", "nivolumab", "pembrolizumab", and "safety" were the search priorities, whereas "multicenter", "resistance", "adverse events", and "renal-cell carcinoma" were seen as emerging topics in this specific field., Conclusion: The bibliometric analysis of the most frequently cited clinical trials with ICIs provided information on the characteristics of the studies evaluated as well as hotpots and trends in evolving immunopharmacotherapy research on ICIs.

The hyper-unstable Chr9p21 locus, harbouring the interferon gene cluster, oncogenes and C9orf72 , is linked to multiple diseases. C9orf72 (GGGGCC)n expansions ( C9orf72 Exp) are associated with incompletely penetrant amyotrophic lateral sclerosis, frontotemporal dementia and autoimmune disorders. C9orf72 Exp patients display hyperactive cGAS-STING-linked interferon immune and DNA damage responses, but the source of immunostimulatory or damaged DNA is unknown. Here, we show C9orf72 Exp in pre-symptomatic and amyotrophic lateral sclerosis-frontotemporal dementia patient cells and brains cause the folate-sensitive chromosomal fragile site, FRA9A. FRA9A centers on >33 kb of C9orf72 as highly compacted chromatin embedded in an 8.2 Mb fragility zone spanning 9p21, encompassing 46 genes, making FRA9A one of the largest fragile sites. C9orf72 Exp cells show chromosomal instability, heightened global- and Chr9p-enriched sister-chromatid exchanges, truncated-Chr9s, acentric-Chr9s and Chr9-containing micronuclei, providing endogenous sources of damaged and immunostimulatory DNA. Cells from one C9orf72 Exp patient contained a highly rearranged FRA9A-expressing Chr9 with Chr9-wide dysregulated gene expression. Somatic C9orf72 Exp repeat instability and chromosomal fragility are sensitive to folate deficiency. Age-dependent repeat instability, chromosomal fragility and chromosomal instability can be transferred to CNS and peripheral tissues of transgenic C9orf72 Exp mice, implicating C9orf72 Exp as the source. Our results highlight unappreciated effects of C9orf72 expansions that trigger vitamin-sensitive chromosome fragility, adding structural variations to the disease-enriched 9p21 locus, and likely elsewhere., (© The Author(s) 2024. Published by Oxford University Press on behalf of NAR Molecular Medicine.)

The hyper-unstable Chr9p21 locus, harbouring the interferon gene cluster, oncogenes and C9orf72, is linked to multiple diseases. C9orf72 (GGGGCC)n expansions ( C9orf72 Exp) are associated with incompletely penetrant amyotrophic lateral sclerosis, frontotemporal dementia and autoimmune disorders. C9orf72 Exp patients display hyperactive cGAS-STING-linked interferon immune and DNA damage responses, but the source of immuno-stimulatory or damaged DNA is unknown. Here, we show C9orf72 Exp in pre-symptomatic and ALS-FTD patient cells and brains cause the folate-sensitive chromosomal fragile site, FRA9A. FRA9A centers on >33kb of C9orf72 as highly-compacted chromatin embedded in an 8.2Mb fragility zone spanning 9p21, encompassing 46 genes, making FRA9A one of the largest fragile sites. C9orf72 Exp cells show chromosomal instability, heightened global- and Chr9p-enriched sister-chromatid exchanges, truncated-Chr9s, acentric-Chr9s and Chr9-containing micronuclei, providing endogenous sources of damaged and immunostimulatory DNA. Cells from one C9orf72 Exp patient contained highly-rearranged FRA9A-expressing Chr9 with Chr9-wide dysregulated gene expression. Somatic C9orf72 Exp repeat instability and chromosomal fragility are sensitive to folate-deficiency. Age-dependent repeat instability, chromosomal fragility, and chromosomal instability can be transferred to CNS and peripheral tissues of transgenic C9orf72 Exp mice, implicating C9orf72 Exp as the source. Our results highlight unappreciated effects of C9orf72 expansions that trigger vitamin-sensitive chromosome fragility, adding structural variations to the disease-enriched 9p21 locus, and likely elsewhere.

Objective: To develop a GC method for simultaneous determination of 4 compounds (atractylone, hinesol, beta-eudesmol and atractylodin) in Atractylodes lancea., Method: A HP-1 capillary column (0.25 mm x 30 m, 0.25 microm) was used. The detector was FID:Inlet temperature was 250 degrees C. The detector temperature was 250 degrees C. The column temperature was set at 145 degrees C and held for 25 min after injection, then programmed at 10 degrees C x min(-1) to 250 degrees C and held for 10 min at the temperature. The carrying gas was nitrogen, split ratio was 40:1. Injection volume was 2 microL, Cluster analysis was performed by SPSS13.0 software., Result: The linear ranges for atractylone, hinesol, beta-eudesmol and atractylodin were 0.0122. 32 (r = .9998), 0.008-1.68 (r = 0.9998), 0.009-1.76 (r = 0.9999), 0.016-3.20 g x L(-1) (r = 0.9997), respectively. The average recoveries (n = 3) of atractylone, hinesol, beta-eudesmol and atractylodin were 98.0%-99.0%, 97.7%-99.4%, 98.4%-99.2%, 97.8%-99.7%, respectively. The samples analyzed were divided into two classes., Conclusion: This method is simple, specific, repeatable and stable. It can be applied for the simultaneous determination of 4 compounds (atractylone, hinesol, beta-eudesmol and atractylodin) in A. lancea, which will provide the basis for the quality control of A. lancea. The contents of 4 active compounds were significantly different between geo-authentic and non-authentic producing areas.