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Molecules (Basel, Switzerland) May 2024L-asparaginases are used in the treatment of acute lymphoblastic leukemia. The aim of this work was to compare the antiproliferative potential and proapoptotic...
L-asparaginases are used in the treatment of acute lymphoblastic leukemia. The aim of this work was to compare the antiproliferative potential and proapoptotic properties of novel L-asparaginases from different structural classes, viz. EcAIII and KpAIII (class 2), as well as ReAIV and ReAV (class 3). The EcAII (class 1) enzyme served as a reference. The proapoptotic and antiproliferative effects were tested using four human leukemia cell models: MOLT-4, RAJI, THP-1, and HL-60. The antiproliferative assay with the MOLT-4 cell line indicated the inhibitory properties of all tested L-asparaginases. The results from the THP-1 cell models showed a similar antiproliferative effect in the presence of EcAII, EcAIII, and KpAIII. In the case of HL-60 cells, the inhibition of proliferation was observed in the presence of EcAII and KpAIII, whereas the proliferation of RAJI cells was inhibited only by EcAII. The results of the proapoptotic assays showed individual effects of the enzymes toward specific cell lines, suggesting a selective (time-dependent and dose-dependent) action of the tested L-asparaginases. We have, thus, demonstrated that novel L-asparaginases, with a lower substrate affinity than EcAII, also exhibit significant antileukemic properties in vitro, which makes them interesting new drug candidates for the treatment of hematological malignancies. For all enzymes, the kinetic parameters (K and k) and thermal stability (T) were determined. Structural and catalytic properties of L-asparaginases from different classes are also summarized.
Topics: Humans; Asparaginase; Antineoplastic Agents; Apoptosis; Cell Proliferation; Cell Line, Tumor; Substrate Specificity; HL-60 Cells; Leukemia
PubMed: 38792133
DOI: 10.3390/molecules29102272 -
Scientific Reports May 2024Behaviors can vary throughout an animal's life and this variation can often be explained by changes associated with learning and/or maturing. Currently, there is little...
Behaviors can vary throughout an animal's life and this variation can often be explained by changes associated with learning and/or maturing. Currently, there is little consensus regarding how these processes interact to affect behaviors. Here we proposed a heuristic approach to disentangle the effects of learning and maturation on behavior and applied it to the predatory behaviors of Physocyclus globosus spiderlings. We varied the degree of prey difficulty and familiarity spiderlings received along the first instar and across the molt to the second instar and quantified the time spiderlings spent wrapping prey, as a proxy for prey capture efficiency. We found no overall evidence for learning or maturation. Changes in efficiency were mainly due to the switch from difficult to easy prey, or vice versa. However, there was one treatment where spiderlings improved in efficiency before and after the molt, without a switch in prey type. This provides some indication that difficult prey may offer more opportunity for learning or maturation to impact behavior. Although we found little effect of learning or maturation on prey capture efficiency, we suggest that our heuristic approach is effective and could be useful in investigating these processes in other behaviors and other animals.
Topics: Animals; Spiders; Predatory Behavior; Learning; Heuristics
PubMed: 38778018
DOI: 10.1038/s41598-024-61252-7 -
BioRxiv : the Preprint Server For... May 2024Apical extracellular matrices (aECMs) are associated with all epithelia and form a protective layer against biotic and abiotic threats in the environment. Despite their...
Apical extracellular matrices (aECMs) are associated with all epithelia and form a protective layer against biotic and abiotic threats in the environment. Despite their importance, we lack a deep understanding of their structure and dynamics in development and disease. molting offers a powerful entry point to understanding developmentally programmed aECM remodeling. A transient matrix is formed in embryos and at the end of each larval stage, presumably to pattern the new cuticle. Focusing on targets of NHR-23, a key transcription factor which drives molting, we identified the Kunitz family protease inhibitor gene as an NHR-23 target. We identified NHR-23-binding sites that are necessary and sufficient for epithelial expression. is necessary to pattern every layer of the adult cuticle, suggesting a broad patterning role prior to the formation of the mature cuticle. MLT-11::mNeonGreen::3xFLAG transiently localized to the aECM in the cuticle and embryo. It was also detected in lining openings to the exterior (vulva, rectum, mouth). Reduction of function disrupted the barrier function of the cuticle. Tissue-specific RNAi suggested activity is primarily necessary in seam cells and we observed alae and seam cell fusion defects upon inactivation. Predicted null mutations caused fully penetrant embryonic lethality and elongation defects suggesting also plays an important role in patterning the embryonic sheath. Finally, we found that inactivation suppressed the blistered cuticle phenotype of mutants of mutants, a subtilisin protease gene but did not affect BLI-4::sfGFP expression. These data could suggest that MLT-11 may be necessary to assure proper levels of BLI-4 activity.
PubMed: 38766248
DOI: 10.1101/2024.05.12.593762 -
BioRxiv : the Preprint Server For... May 2024The mammalian PAS-domain protein PERIOD (PER) and its orthologue LIN-42 have been proposed to constitute an evolutionary link between two distinct, circadian and...
The mammalian PAS-domain protein PERIOD (PER) and its orthologue LIN-42 have been proposed to constitute an evolutionary link between two distinct, circadian and developmental, timing systems. However, while the function of PER in animal circadian rhythms is well understood molecularly and mechanistically, this is not true for the function of LIN-42 in timing rhythmic development. Here, using targeted deletions, we find that the LIN-42 PAS domains are dispensable for the protein's function in timing molts. Instead, we observe arrhythmic molts upon deletion of a distinct sequence element, conserved with PER. We show that this element mediates stable binding to KIN-20, the CK1δ/ε orthologue. We demonstrate that CK1δ phosphorylates LIN-42 and define two conserved helical motifs, CK1δ-binding domain A (CK1BD-A) and CK1BD-B, that have distinct roles in controlling CK1δ-binding and kinase activity . KIN-20 and the LIN-42 CK1BD are required for proper molting timing . These interactions mirror the central role of a stable circadian PER-CK1 complex in setting a robust ~24-hour period. Hence, our results establish LIN-42/PER - KIN-20/CK1δ/ε as a functionally conserved signaling module of two distinct chronobiological systems.
PubMed: 38766223
DOI: 10.1101/2024.05.09.593322 -
Research Square Apr 2024Natural killer (NK) cells are important effectors of the innate immune system. Unlike T cells, NK cells do not require antigen-priming, making them an important...
Natural killer (NK) cells are important effectors of the innate immune system. Unlike T cells, NK cells do not require antigen-priming, making them an important first-line of defense against malignant cells. Because of the potential for increased cancer risk as a result of astronaut exposure to space radiation, we performed studies to determine whether conditions of microgravity present during spaceflight affects the body's natural defenses against leukemogenesis. Human NK cells were cultured for 48 hours under normal gravity and simulated microgravity (sµG), and cytotoxicity against K-562 (CML) and MOLT-4 (T-ALL) cell lines was measured using standard methodology or under continuous conditions of sµG. Even this brief exposure to sµG markedly reduced NK cytotoxicity against both leukemic cells using standard assay procedures, and these deleterious effects were even more pronounced in continuous sµG. RNA-seq performed on NK cells from two healthy donors provided insight into the mechanism(s) by which sµG reduced cytotoxicity. Given our prior report that human HSC exposed to simulated space radiation gave rise to T-ALL , the reduced cytotoxicity against MOLT-4 is striking and raises the possibility that µG may add to astronaut risk of leukemogenesis during prolonged missions beyond LEO.
PubMed: 38746365
DOI: 10.21203/rs.3.rs-3972868/v1 -
BMC Complementary Medicine and Therapies May 2024Cepharanthin alone or in combination with glucocorticoid (GC) has been used to treat chronic immune thrombocytopenia (ITP) since the 1990s. Cepharanthine (CEP) is one of...
Cepharanthine synergistically promotes methylprednisolone pharmacodynamics against human peripheral blood mononuclear cells possibly via regulation of P-glycoprotein/glucocorticoid receptor translocation.
BACKGROUND
Cepharanthin alone or in combination with glucocorticoid (GC) has been used to treat chronic immune thrombocytopenia (ITP) since the 1990s. Cepharanthine (CEP) is one of the main active components of Cepharanthin. The purpose of this study was to investigate the effects of CEP on GC pharmacodynamics on immune cells and analyse the possible action mechanism of their interactions.
METHODS
Peripheral blood mononuclear cells (PBMCs), T lymphocytic leukemia MOLT-4 cells and daunorubicin resistant MOLT-4 cells (MOLT-4/DNR) were used to evaluate the pharmacodynamics and molecular mechanisms. Drug pharmacodynamics was evaluated by WST-8 assay. P-glycoprotein function was examined by rhodamine 123 assay. CD4CD25Foxp3 regulatory T cells and Th1/Th2/Th17 cytokines were detected by flow cytometry. P-glycoprotein expression and GC receptor translocation were examined by Western blot.
RESULTS
CEP synergistically increased methylprednisolone (MP) efficacy with the suppressive effect on the cell viability of PBMCs. 0.3 and 1 μM of CEP significantly inhibited P-glycoprotein efflux function of CD4 cells, CD8 cells, and lymphocytes (P<0.05). 0.03~3 μM of CEP also inhibited the P-glycoprotein efflux function in MOLT-4/DNR cells in a concentration-dependent manner (P<0.001). However, 0.03~3 μM of CEP did not influence P-glycoprotein expression. 0.03~0.3 μM of CEP significantly increased the GC receptor distribution from the cytoplasm to the nucleus in a concentration-dependent manner in MOLT-4/DNR cells. The combination did not influence the frequency of CD4, CD4CD25 and CD4CD25Foxp3 T cells or the secretion of Th1/Th2/Th17 cytokines from PBMCs. In contrast, CEP alone at 1 μM decreased the percentage of CD4 T cell significantly (P<0.01). It also inhibited the secretion of IL-6, IL-10, IL-17, TNF-α, and IFN-γ.
CONCLUSIONS
CEP synergistically promoted MP pharmacodynamics to decrease the cell viability of the mitogen-activated PBMCs, possibly via inhibiting P-glycoprotein function and potentiating GC receptor translocation. The present study provides new evidence of the therapeutic effect of Cepharanthin alone or in combination with GC for the management of chronic ITP.
Topics: Humans; Benzylisoquinolines; Leukocytes, Mononuclear; ATP Binding Cassette Transporter, Subfamily B, Member 1; Methylprednisolone; Receptors, Glucocorticoid; Drug Synergism; Benzodioxoles
PubMed: 38734604
DOI: 10.1186/s12906-024-04489-z -
ACS Catalysis May 2024Arginine phosphorylation plays numerous roles throughout biology. Arginine kinase (AK) catalyzes the delivery of an anionic phosphoryl group (PO) from ATP to a planar,...
Arginine phosphorylation plays numerous roles throughout biology. Arginine kinase (AK) catalyzes the delivery of an anionic phosphoryl group (PO) from ATP to a planar, trigonal nitrogen in a guanidinium cation. Density functional theory (DFT) calculations have yielded a model of the transition state (TS) for the AK-catalyzed reaction. They reveal a network of over 50 hydrogen bonds that delivers unprecedented pyramidalization and out-of-plane polarization of the arginine guanidinium nitrogen (Nη2) and aligns the electron density on Nη2 with the scissile P-O bond, leading to in-line phosphoryl transfer via an associative mechanism. In the reverse reaction, the hydrogen-bonding network enforces the conformational distortion of a bound phosphoarginine substrate to increase the basicity of Nη2. This enables Nη2 protonation, which triggers PO migration to generate ATP. This polarization-pyramidalization of nitrogen in the arginine side chain is likely a general phenomenon that is exploited by many classes of enzymes mediating the post-translational modification of arginine.
PubMed: 38721379
DOI: 10.1021/acscatal.4c00380 -
Journal of Insect Science (Online) May 2024The mealworm Tenebrio molitor L. (Coleoptera: Tenebrionidae) feeds on wheat bran and is considered both a pest and an edible insect. Its larvae contain proteins and...
The mealworm Tenebrio molitor L. (Coleoptera: Tenebrionidae) feeds on wheat bran and is considered both a pest and an edible insect. Its larvae contain proteins and essential amino acids, fats, and minerals, making them suitable for animal and human consumption. Zearalenone (ZEA) is the mycotoxin most commonly associated with Fusarium spp. It is found in cereals and cereal products, so their consumption is a major risk for mycotoxin contamination. One of the most important effects of ZEA is the induction of oxidative stress, which leads to physiological and behavioral changes. This study deals with the effects of high doses of ZEA (10 and 20 mg/kg) on survival, molting, growth, weight gain, activity of antioxidant enzymes superoxide dismutase (SOD) and glutathione S-transferase (GST), and locomotion of mealworm larvae. Both doses of ZEA were found to (i) have no effect on survival, (ii) increase molting frequency, SOD, and GST activity, and (iii) decrease body weight and locomotion, with more pronounced changes at 20 mg/kg. These results indicated the susceptibility of T. molitor larvae to high doses of ZEA in feed.
Topics: Animals; Tenebrio; Larva; Zearalenone; Glutathione Transferase; Locomotion; Superoxide Dismutase; Antioxidants
PubMed: 38717261
DOI: 10.1093/jisesa/ieae052 -
Marine Pollution Bulletin Jul 2024We exposed adult individuals of the sentinel mangrove crab Minuca rapax to waterborne microplastics (MP; 53-63 μm polyethylene spheres) in a long-term experiment...
We exposed adult individuals of the sentinel mangrove crab Minuca rapax to waterborne microplastics (MP; 53-63 μm polyethylene spheres) in a long-term experiment (56 days). Weassessed 1) MP effects on growth, survival, and food intake. and 2) the MP tissue acumulation and its reduction of body burden through feces and molting. MP exposure did not affect growth and survival. The hepatopancreas accumulated more MP than the gills and muscle. Most of the ingested MP particles were released in the feces and molts, indicating a rapid passage through the digestive tract. MP impaired food intake of M. rapax, with unknown consequences to the local populations. These results provide insights on MP translocation mechanisms, its elimination and toxicity associated with MP.
Topics: Animals; Brachyura; Water Pollutants, Chemical; Microplastics; Feces; Molting; Environmental Monitoring; Hepatopancreas
PubMed: 38688757
DOI: 10.1016/j.marpolbul.2024.116410 -
Insects Mar 2024Fushi-tarazu factor 1 (FTZ-F1) is a class of transcription factors belonging to the nuclear receptor superfamily and an important molting regulator in insects; however,...
Fushi-tarazu factor 1 (FTZ-F1) is a class of transcription factors belonging to the nuclear receptor superfamily and an important molting regulator in insects; however, its detailed function in the molting process of is still unclear. This study identified two FTZ-F1 transcripts ( and ) in . The classical domains of FTZ-F1 were present in their protein sequences and distinguished based on their variable N-terminal domains. Reverse-transcription quantitative polymerase chain reaction analysis revealed that and were highly expressed in the integument. RNA interference (RNAi) was used to explore the function of s in the molting of the third-instar nymph. Separate or silencing did not affect the normal development of third-instar nymphs; however, the simultaneous RNAi of and caused the nymphs to be trapped in the third instar stage and finally die. Furthermore, the hematoxylin-eosin and chitin staining of the cuticle showed that the new cuticles were thickened after silencing the s compared to the controls. RNA-seq analysis showed that genes encoding four cuticle proteins, two chitin synthesis enzymes, and cytochrome P450 303a1 were differentially expressed between ds- and dss-injected groups. Taken together, and are involved in the ecdysis of locusts, possibly by regulating the expression of genes involved in cuticle formation, chitin synthesis, and other key molting processes.
PubMed: 38667367
DOI: 10.3390/insects15040237