A fattening factor to quantify the accumulation ability of microorganisms under N-starvation

2021 ◽  
Author(s):  
Fabrizio Di Caprio
Keyword(s):  
N Starvation ◽  
Accumulation Ability

scholarly journals Biomarkers in Pancreatic Cancer as Analytic Targets for Nanomediated Imaging and Therapy

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3083
Author(s):  
Cristiana Maria Grapa ◽  
Lucian Mocan ◽  
Dana Crisan ◽  
Mira Florea ◽  
Teodora Mocan
Keyword(s):  
Drug Delivery ◽  
Pancreatic Cancer ◽  
Targeted Delivery ◽  
Drug Toxicity ◽  
Treatment Options ◽  
Tumor Stroma ◽  
Chemotherapy Response ◽  
Rising Incidence ◽  
Tumor Accumulation ◽  
Accumulation Ability

As the increase in therapeutic and imaging technologies is swiftly improving survival chances for cancer patients, pancreatic cancer (PC) still has a grim prognosis and a rising incidence. Practically everything distinguishing for this type of malignancy makes it challenging to treat: no approved method for early detection, extended asymptomatic state, limited treatment options, poor chemotherapy response and dense tumor stroma that impedes drug delivery. We provide a narrative review of our main findings in the field of nanoparticle directed treatment for PC, with a focus on biomarker targeted delivery. By reducing drug toxicity, increasing their tumor accumulation, ability to modulate tumor microenvironment and even improve imaging contrast, it seems that nanotechnology may one day give hope for better outcome in pancreatic cancer. Further conjugating nanoparticles with biomarkers that are overexpressed amplifies the benefits mentioned, with potential increase in survival and treatment response.

UCNP@BSA@Ru nanoparticles with tumor-specific and NIR-triggered efficient PACT activity in vivo

2021 ◽  
Author(s):  
Chao Zhang ◽  
Xusheng Guo ◽  
Xuwen Da ◽  
Yishan Yao ◽  
Haihua Xiao ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Short Wavelength ◽  
Ru Nanoparticles ◽  
Wavelength Absorption ◽  
Tumor Accumulation ◽  
Accumulation Ability

Ru(II)-based photoactivated chemotherapy (PACT) agents are promising, however, the short wavelength absorption (generally < 550 nm) and poor tumor accumulation ability limit their in vivo applications. Herein bovine serum albumin...

scholarly journals Nitrogen starvation and stationary phase lipophagy have distinct molecular mechanisms

2020 ◽  
Author(s):  
Ravinder Kumar ◽  
Muhammad Arifur Rahman ◽  
Taras Y. Nazarko
Keyword(s):  
Lipid Droplets ◽  
Molecular Mechanisms ◽  
Nitrogen Starvation ◽  
S Phase ◽  
Carbon Limitation ◽  
Intracellular Lipid ◽  
Selective Autophagy ◽  
The Core ◽  
Vacuole Fusion ◽  
N Starvation

AbstractIn yeast, the selective autophagy of intracellular lipid droplets (LDs) or lipophagy can be induced by either nitrogen (N) starvation or carbon limitation (e.g. in the stationary (S) phase). We developed the yeast, Komagataella phaffii (formerly Pichia pastoris), as a new lipophagy model and compared the N-starvation and S-phase lipophagy in over 30 autophagy-related mutants using the Erg6-GFP processing assay. Surprisingly, two lipophagy pathways had hardly overlapping stringent molecular requirements. While the N-starvation lipophagy strictly depended on the core autophagic machinery (Atg1-Atg9, Atg18 and Vps15), vacuole fusion machinery (Vam7 and Ypt7) and vacuolar proteolysis (proteinases A and B), only Atg6 and proteinases A and B were essential for the S-phase lipophagy. The rest of the proteins were only partially required in the S-phase. Moreover, we isolated the prl1 (for positive regulator of lipophagy 1) mutant affected in the S-phase lipophagy but not N-starvation lipophagy. The prl1 defect was at a stage of delivery of the LDs from the cytoplasm to the vacuole further supporting mechanistically different nature of the two lipophagy pathways. Taken together, our results suggest that N-starvation and S-phase lipophagy have distinct molecular mechanisms.

The gastropod Arion fuscus prefers cyanobacterial to green algal parts of the tripartite lichen Nephroma arcticum due to low chemical defence

2009 ◽  
Vol 42 (1) ◽  
pp. 113-117 ◽  
Author(s):  
Johan ASPLUND ◽  
Yngvar GAUSLAA
Keyword(s):  
Usnic Acid ◽  
Chemical Defence ◽  
Secondary Compounds ◽  
Distribution Limit ◽  
Green Algal ◽  
Defensive Role ◽  
N Starvation ◽  
And Control ◽  
Terricolous Lichen ◽  
Acetone Rinsing

AbstractAlthough the tripartite terricolous lichen Nephroma arcticum is easily accessible to lichen-feeding gastropods, grazing marks are mainly restricted to localized cephalodia with N-fixing Nostoc. We tested if this gastropod preference for cephalodia can be explained by differences in carbon based secondary compounds (CBSCs) in cyanobacterial versus green-algal tissues. CBSCs were non-destructively removed from air-dry thalli by 100% acetone. Compound deficient and control thallus parts were offered to the slug Arion fuscus and grazing preferences were quantified by area measurements in ArcGIS™. The concentrations of CBSCs (phenarctin, usnic acid, nephroarctin and methyl gyrophorate) in thallus parts with and without cephalodia were quantified with HPLC. Compared to purely green-algal parts, cephalodial parts with adjoining fungal tissues contained less defensive compounds, and were preferred by A. fuscus. The cephalodia themselves do not contain any CBSCs. After acetone rinsing, A. fuscus did not discriminate between green-algal and cyanobacterial parts. The results were consistent with the hypothesis that CBSCs in green-algal parts of N. arcticum play a herbivore-defensive role. It is further hypothesized that grazing of cephalodia may lead to N-starvation and reduced growth of N. arcticum thalli in southern portions of its range where lichenivorous gastropods are more abundant. This may play a role in shaping the southern distribution limit of this arctic-boreal lichen species.

scholarly journals The establishment of new protein expression system using N starvation inducible promoters in Chlorella

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jun-Hye Shin ◽  
Juyoung Choi ◽  
Jeongmin Jeon ◽  
Manu Kumar ◽  
Juhyeon Lee ◽  
...  
Keyword(s):  
Protein Expression ◽  
Expression System ◽  
Inducible Promoters ◽  
Protein Expression System ◽  
N Starvation ◽  
New Protein

Stimulation of Strontium Accumulation in Linoleate-Enriched Saccharomyces cerevisiae Is a Result of Reduced Sr2+ Efflux

1999 ◽  
Vol 65 (3) ◽  
pp. 1191-1197 ◽  
Author(s):  
Simon V. Avery ◽  
Shareeka L. Smith ◽  
A. Mohamad Ghazi ◽  
Michael J. Hoptroff
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Plasma Membrane ◽  
Fatty Acid ◽  
Atpase Inhibitor ◽  
Calmodulin Antagonist ◽  
Wide Range ◽  
Fatty Acid Supplement ◽  
Accumulation Ability ◽  
Stimulation Of

ABSTRACT The influence of modified plasma membrane fatty acid composition on cellular strontium accumulation in Saccharomyces cerevisiaewas investigated. Growth of S. cerevisiae in the presence of 1 mM linoleate (18:2) (which results in 18:2 incorporation to ∼70% of total cellular and plasma membrane fatty acids, with no effect on growth rate) yielded cells that accumulated Sr2+ intracellularly at approximately twice the rate ofS. cerevisiae grown without a fatty acid supplement. This effect was evident over a wide range of external Sr2+concentrations (25 μM to 5 mM) and increased with the extent of cellular 18:2 incorporation. Stimulation of Sr2+accumulation was not evident following enrichment of S. cerevisiae with either palmitoleate (16:1), linolenate (18:3) (n-3 and n-6 isomers), or eicosadienoate (20:2) (n-6 and n-9 isomers). Competition experiments revealed that Ca2+- and Mg2+-induced inhibition of Sr2+ accumulation did not differ between unsupplemented and 18:2-supplemented cells. Treatment with trifluoperazine (TFP) (which can act as a calmodulin antagonist and Ca2+-ATPase inhibitor), at a low concentration that precluded nonspecific K+ efflux, increased intracellular Sr2+ accumulation by approximately 3.6- and 1.4-fold in unsupplemented and 18:2-supplemented cells, respectively. Thus, TFP abolished the enhanced Sr2+ accumulation ability of 18:2-supplemented cells. Moreover, the rate of Sr2+release from Sr2+-loaded fatty acid-unsupplemented cells was found to be at least twice as great as that from Sr2+-loaded 18:2-enriched cells. The influence of enrichment with other fatty acids on Sr2+ efflux was variable. The results reveal an enhanced Sr2+ accumulation ability of S. cerevisiae following 18:2-enrichment, which is attributed to diminished Sr2+ efflux activity in these cells.

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