The process of localizing a maternal messenger RNA in Xenopus oocytes

Development ◽  
1989 ◽  
Vol 107 (Supplement) ◽  
pp. 31-36
Author(s):  
Joel K. Yisraeli ◽  
Sergei Sokol ◽  
D. A. Melton
Keyword(s):  
Late Stage ◽  
Messenger Rna ◽  
Early Stage ◽  
Stage Iv ◽  
Microtubule Inhibitors ◽  
Maternal Mrna ◽  
Vegetal Cortex ◽  
Vegetal Pole ◽  
Cytoplasmic Microtubules

The maternal mRNA Vgl is localized to the vegetal pole during oogenesis in Xenopus. We have cultured oocytes in vitro to begin to understand how this localization occurs. Endogenous Vgl mRNA undergoes localization when oocytes are cultured in vitro, and synthetic Vgl mRNA injected into such oocytes is localized in the same fashion. Vgl mRNA is associated with a detergentinsoluble fraction from homogenized oocytes, suggesting a possible cytoskeletal association. The use of cytoskeletal inhibitors reveals a two-step process for localizing Vgl mRNA. Microtubule inhibitors such as nocodazole and colchicine inhibit the localization of Vgl mRNA in late stage III/early stage IV oocytes, but have no effect on Vgl mRNA once it is localized. The microfilament inhibitor cytochalasin B, however, has little effect on thetranslocation of Vgl mRNA in middle-stage oocytes but causes a release of the message in late-stage oocytes. We propose a model for the localization of Vgl mRNA in which translocation of the message to the vegetal cortex is achieved via cytoplasmic microtubules and the anchoring of the message at the cortex involves cortical microfilaments.

scholarly journals Context-Specific Efficacy of Apalutamide Therapy in Preclinical Models of Pten-Deficient Prostate Cancer

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 3975
Author(s):  
Marco A. De Velasco ◽  
Yurie Kura ◽  
Naomi Ando ◽  
Noriko Sako ◽  
Eri Banno ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Antitumor Activity ◽  
Cancer Cells ◽  
Late Stage ◽  
Early Stage ◽  
Castration Resistant Prostate Cancer ◽  
Akt Inhibitor ◽  
Molecular Features ◽  
Context Specific

Significant improvements with apalutamide, a nonsteroidal antiandrogen used to treat patients suffering from advanced prostate cancer (PCa), have prompted evaluation for additional indications and therapeutic development with other agents; however, persistent androgen receptor (AR) signaling remains problematic. We used autochthonous mouse models of Pten-deficient PCa to examine the context-specific antitumor activity of apalutamide and profile its molecular responses. Overall, apalutamide showed potent antitumor activity in both early-stage and late-stage models of castration-naïve prostate cancer (CNPC). Molecular profiling by Western blot and immunohistochemistry associated persistent surviving cancer cells with upregulated AKT signaling. While apalutamide was ineffective in an early-stage model of castration-resistant prostate cancer (CRPC), it tended to prolong survival in late-stage CRPC. Molecular features associated with surviving cancer cells in CRPC included upregulated aberrant-AR, and phosphorylated S6 and proline-rich Akt substrate of 40 kDa (PRAS40). Strong synergy was observed with the pan-AKT inhibitor GSK690693 and apalutamide in vitro against the CNPC- and CRPC-derived cell lines and tended to improve the antitumor responses in CNPC but not CRPC in vivo. Upregulation of signal transducer and activator of transcription 3 (STAT3) and proviral insertion in murine-1 (PIM-1) were associated with combined apalutamide/GSK690693. Our findings show that apalutamide can attenuate Pten-deficient PCa in a context-specific manner and provides data that can be used to further study and, possibly, develop additional combinations with apalutamide.

XMAP230 is required for the assembly and organization of acetylated microtubules and spindles in Xenopus oocytes and eggs

1998 ◽  
Vol 111 (16) ◽  
pp. 2315-2327 ◽  
Author(s):  
B.J. Cha ◽  
B. Error ◽  
D.L. Gard
Keyword(s):  
Late Stage ◽  
Xenopus Oocytes ◽  
Early Stage ◽  
Polyclonal Antibodies ◽  
Stage Iv ◽  
Stage I ◽  
Meiotic Spindle ◽  
Heat Stable ◽  
Early Embryos ◽  
And Function

We used affinity-purified polyclonal antibodies to characterize the distribution and function of XMAP230, a heat-stable microtubule-associated protein isolated from Xenopus eggs, during oogenesis. Immunoblots revealed that XMAP230 was present throughout oogenesis and early development, but was most abundant in late stage oocytes, eggs, and early embryos. Immunofluorescence microscopy revealed that XMAP230 was associated with microtubules in oogonia, post-mitotic stage 0 oocytes, early stage I oocytes, and during stage IV-VI of oogenesis. However, staining of microtubules by anti-XMAP230 was not detectable during late stage I through stage III. In stage VI oocytes, anti-XMAP230 stained a large subset of microtubules that were also stained with monoclonal antibodies specific for acetylated (α)-tubulin. During oocyte maturation, XMAP230 was associated with the transient microtubule array that serves as the precursor of the first meiotic spindle, as well as both first and second meiotic spindles. The extensive array of cytoplasmic microtubules present throughout maturation was not detectably stained by anti-XMAP230. Microinjection of anti-XMAP230 locally disrupted the organization and acetylation of microtubules in stage VI oocytes, and reduced the re-acetylation of microtubules during recovery from cold-induced microtubule disassembly. Subsequent maturation of oocytes injected with anti-XMAP230 resulted in defects in the assembly of the transient microtubules array and first meiotic spindle. These observations suggest that XMAP230 is required for the stabilization and organization of cytoplasmic and spindle microtubules in Xenopus oocytes and eggs.

scholarly journals Paraquat Preferentially Induces Apoptosis of Late Stage Effector Lymphocyte and Impairs Memory Immune Response in Mice

2019 ◽  
Vol 16 (11) ◽  
pp. 2060 ◽  
Author(s):  
Yiming Shao ◽  
Yifan Zhao ◽  
Tingting Zhu ◽  
Fen Zhang ◽  
Xiuli Chang ◽  
...  
Keyword(s):  
Immune Response ◽  
Late Stage ◽  
Early Stage ◽  
Keyhole Limpet Hemocyanin ◽  
Primary Immune Response ◽  
Secondary Immune Response ◽  
Effector Cells ◽  
Memory Immune Response ◽  
The Impact

Paraquat (PQ) is a toxic non-selective herbicide. To date, the effect of PQ on memory immune response is still unknown. We investigated the impact of PQ on memory immune response. Adult C57BL/6 mice were subcutaneously injected with 2 mg/kg PQ, 20 mg/kg PQ or vehicle control every three days for two weeks. A single injection of keyhole limpet hemocyanin (KLH) at day four after the initial PQ treatment was used to induce a primary immune response; a second KLH challenge was performed at three months post the first KLH immunization to induce a secondary immune response. In steady state, treatment with 20 mg/kg PQ reduced the level of serum total IgG, but not that of IgM; treatment with 20 mg/kg PQ decreased the number of effector and memory lymphocytes, but not naïve or inactivated lymphocytes. During the primary immune response to KLH, treatment with 20 mg/kg PQ did not influence the proliferation of lymphocytes or expression of co-stimulatory molecules. Instead, treatment with 20 mg/kg PQ increased the apoptosis of lymphocytes at late stage, but not early stage of the primary immune response. During the secondary immune response to KLH, treatment with 20 mg/kg PQ reduced the serum anti-KLH IgG and KLH-responsive CD4 T cells and B cells. Moreover, effector or activated lymphocytes were more sensitive to PQ-induced apoptosis in vitro. Treatment with 2 mg/kg PQ did not impact memory immune response to KLH. Thus, treatment with 20 mg/kg PQ increased apoptosis of late stage effector cells to yield less memory cells and thereafter impair memory immune response, providing a novel understanding of the immunotoxicity of PQ.

scholarly journals Involvement of Clostridium botulinum ATCC 3502 Sigma Factor K in Early-Stage Sporulation

2012 ◽  
Vol 78 (13) ◽  
pp. 4590-4596 ◽  
Author(s):  
David G. Kirk ◽  
Elias Dahlsten ◽  
Zhen Zhang ◽  
Hannu Korkeala ◽  
Miia Lindström
Keyword(s):  
Late Stage ◽  
Sigma Factor ◽  
Parent Strain ◽  
Clostridium Botulinum ◽  
Early Stage ◽  
Gene Knockout ◽  
Model Organism ◽  
Stage Iv ◽  
Pcr Analysis ◽  
Content Type

ABSTRACTA key survival mechanism ofClostridium botulinum, the notorious neurotoxic food pathogen, is the ability to form heat-resistant spores. While the genetic mechanisms of sporulation are well understood in the model organismBacillus subtilis, nothing is known about these mechanisms inC. botulinum.Using the ClosTron gene-knockout tool,sigK, encoding late-stage (stage IV) sporulation sigma factor K inB. subtilis, was disrupted inC. botulinumATCC 3502 to produce two different mutants with distinct insertion sites and orientations. Both mutants were unable to form spores, and their elongated cell morphology suggested that the sporulation pathway was blocked at an early stage. In contrast,sigK-complemented mutants sporulated successfully. Quantitative real-time PCR analysis ofsigKin the parent strain revealed expression at the late log growth phase in the parent strain. Analysis ofspo0A, encoding the sporulation master switch, in thesigKmutant and the parent showed significantly reduced relative levels ofspo0Aexpression in thesigKmutant compared to the parent strain. Similarly,sigFshowed significantly lower relative transcription levels in thesigKmutant than the parent strain, suggesting that the sporulation pathway was blocked in thesigKmutant at an early stage. We conclude that σKis essential for early-stage sporulation inC. botulinumATCC 3502, rather than being involved in late-stage sporulation, as reported for the sporulation model organismB. subtilis. Understanding the sporulation mechanism ofC. botulinumprovides keys to control the public health risks that the spores of this dangerous pathogen cause through foods.

scholarly journals De-escalation Antibiotic Therapy Alleviates Organ Injury through Modulation of NET Formation during Sepsis

2020 ◽  
Author(s):  
Tian Xie ◽  
Chengnan Chu ◽  
Shilong Sun ◽  
Xinyu Wang ◽  
Zehua Duan ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Late Stage ◽  
Early Stage ◽  
Neutrophil Extracellular Trap ◽  
Organ Injury ◽  
Control Group ◽  
Histopathological Analysis ◽  
Escalation Therapy ◽  
Significant Difference

Empiric broad-spectrum antimicrobials therapy is suggested to be started immediately for sepsis patients. Empiric antimicrobial therapy should be narrowed once pathogen identification and sensitivities are established. However, the detail mechanisms of de-escalation strategy are still unclear. Here we hypothesized neutrophil extracellular trap (NETs) played an essential role and de-escalation strategy might alleviate organs injury through regulation of NETs formation in sepsis. We evaluated the effect of imipenem and ceftriaxone on NETs formation in vitro and examined the role of reactive oxygen species (ROS). Next, we designed de-escalation and escalation strategy based on their effects on NETs formation in CLP model. Organ injury, inflammatory cytokines, NETs levels were compared and evaluated. The in vitro study showed that imipenem and ceftriaxone had opposite effects on NETs formation in activated neutrophils. De-escalation therapy resulted in an evaluated MPO-DNA during early stage and decreased MPO-DNA during late stage, which exerted the reverse effects in escalation therapy sepsis animal model. Inflammatory response and organ injury exacerbated when eliminated NETs with DNAseI during early stage of sepsis (p<0.01). Histopathological analysis showed decreased injury in lung, liver and intestine in de-escalation therapy compared with escalation therapy (p<0.01). De-escalation therapy results in the highest 6-day survival rate compared with the control group (p<0.01), however, no significant difference was found between de-escalation and escalation group (p=0.051). We demonstrate that de-escalation, not escalation, therapy reduces organ injury, decreases inflammatory response by promoting NETs formation in the early stage and inhibiting NETs formation in the late stage of sepsis.

scholarly journals De-escalation antibiotic therapy alleviates organ injury through modulation of NETs formation during sepsis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Zehua Duan ◽  
Tian Xie ◽  
Chengnan Chu ◽  
Fang Chen ◽  
Xinyu Wang ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Late Stage ◽  
Early Stage ◽  
Organ Injury ◽  
Control Group ◽  
Histopathological Analysis ◽  
Dependent Manner ◽  
Escalation Therapy ◽  
Significant Difference

AbstractEmpiric broad-spectrum antimicrobials therapy is suggested to be started immediately for sepsis patients. Empiric antimicrobial therapy should be narrowed once pathogen identification and sensitivities are established. However, the detailed mechanisms of de-escalation strategy are still unclear. Here we hypothesized neutrophil extracellular traps (NETs) played an essential role and de-escalation strategy might alleviate organs injury through regulation of NETs formation in sepsis. We evaluated the effect of imipenem and ceftriaxone on NETs formation in vitro and examined the role of reactive oxygen species (ROS). Next, we designed de-escalation and escalation strategy in cecum ligation and puncture (CLP) models. Organ injury, inflammatory cytokines, NETs levels were compared and evaluated. In CLP models, de-escalation therapy resulted in an increased serum MPO-DNA level during the early stage and decreased MPO-DNA level during late stage, which exerted the reverse effects in escalation therapy. Inflammatory response and organ injury exacerbated when eliminated NETs with DNAse I during the early stage of sepsis (p < 0.01). Histopathological analysis showed decreased injury in lung, liver, and intestine in de-escalation therapy compared with escalation therapy (p < 0.01). De-escalation therapy results in the highest 6-day survival rate compared with the control group (p < 0.01), however, no significant difference was found between de-escalation and escalation group (p = 0.051). The in vitro study showed that the imipenem could promote, while the ceftriaxone could inhibit the formation of NETs in PMA-activated PMNs through a ROS-dependent manner. We firstly demonstrate that de-escalation, not escalation, therapy reduces organ injury, decreases inflammatory response by promoting NETs formation in the early stage, and inhibiting NETs formation in the late stage of sepsis.

scholarly journals Early-stage bilayer tissue-engineered skin substitute formed by adult skin progenitor cells produces an improved skin structure in vivo

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Qun Zhang ◽  
Jie Wen ◽  
Chang Liu ◽  
Chuan Ma ◽  
Fuxiang Bai ◽  
...  
Keyword(s):  
Wound Healing ◽  
Progenitor Cells ◽  
Late Stage ◽  
Early Stage ◽  
Hair Follicles ◽  
Immunofluorescent Staining ◽  
Type I ◽  
Apoptotic Pathway ◽  
Skin Structure

Abstract Background In recent years, significant progress has been made in developing highly complex tissue-engineered skin substitutes (TESSs) for wound healing. However, the lack of skin appendages, such as hair follicles and sweat glands, and the time required, are two major limitations that hinder its broad application in the clinic. Therefore, it is necessary to develop a competent TESS in a short time to meet the needs for clinical applications. Methods Adult scalp dermal progenitor cells and epidermal stem cells together with type I collagen as a scaffold material were used to reconstitute bilayer TESSs in vitro. TESSs at 4 different culture times (5, 9, 14, and 21 days) were collected and then grafted onto full-thickness wounds created in the dorsal skin of athymic nude/nude mice. The skin specimens formed from grafted TESSs were collected 4 and 8 weeks later and then evaluated for their structure, cell organization, differentiation status, vascularization, and formation of appendages by histological analysis, immunohistochemistry, and immunofluorescent staining. Results Early-stage bilayer TESSs after transplantation had a better efficiency of grafting. A normal structure of stratified epidermis containing multiple differentiated layers of keratinocytes was formed in all grafts from both early-stage and late-stage TESSs, but higher levels of the proliferation marker Ki-67 and the epidermal progenitor marker p63 were found in the epidermis formed from early-stage TESSs. Interestingly, the transplantation of early-stage TESSs produced a thicker dermis that contained more vimentin- and CD31-positive cells, and importantly, hair follicle formation was only observed in the skin grafted from early-stage TESSs. Finally, early-stage TESSs expressed high levels of p63 but had low expression levels of genes involved in the activation of the apoptotic pathway compared to the late-stage TESSs in vitro. Conclusions Early-stage bilayer TESSs reconstituted from skin progenitor cells contained more competent cells with less activation of the apoptotic pathway and produced a better skin structure, including hair follicles associated with sebaceous glands, after transplantation, which should potentially provide better wound healing when applied in the clinic in the future.

scholarly journals The Artemiside-Artemisox-Artemisone-M1 Tetrad: Efficacies against Blood Stage P. falciparum Parasites, DMPK Properties, and the Case for Artemiside

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2066
Author(s):  
Liezl Gibhard ◽  
Dina Coertzen ◽  
Janette Reader ◽  
Mariëtte E. van der Watt ◽  
Lyn-Marie Birkholtz ◽  
...  
Keyword(s):  
Late Stage ◽  
Early Stage ◽  
Blood Stage ◽  
Combination Therapies ◽  
Prolonged Incubation ◽  
Model Following ◽  
Synthetic Accessibility ◽  
Artemisinin Combination Therapies

Because of the need to replace the current clinical artemisinins in artemisinin combination therapies, we are evaluating fitness of amino-artemisinins for this purpose. These include the thiomorpholine derivative artemiside obtained in one scalable synthetic step from dihydroartemisinin (DHA) and the derived sulfone artemisone. We have recently shown that artemiside undergoes facile metabolism via the sulfoxide artemisox into artemisone and thence into the unsaturated metabolite M1; DHA is not a metabolite. Artemisox and M1 are now found to be approximately equipotent with artemiside and artemisone in vitro against asexual P. falciparum (Pf) blood stage parasites (IC50 1.5–2.6 nM). Against Pf NF54 blood stage gametocytes, artemisox is potently active (IC50 18.9 nM early-stage, 2.7 nM late-stage), although against the late-stage gametocytes, activity is expressed, like other amino-artemisinins, at a prolonged incubation time of 72 h. Comparative drug metabolism and pharmacokinetic (DMPK) properties were assessed via po and iv administration of artemiside, artemisox, and artemisone in a murine model. Following oral administration, the composite Cmax value of artemiside plus its metabolites artemisox and artemisone formed in vivo is some 2.6-fold higher than that attained following administration of artemisone alone. Given that efficacy of short half-life rapidly-acting antimalarial drugs such as the artemisinins is associated with Cmax, it is apparent that artemiside will be more active than artemisone in vivo, due to additive effects of the metabolites. As is evident from earlier data, artemiside indeed possesses appreciably greater efficacy in vivo against murine malaria. Overall, the higher exposure levels of active drug following administration of artemiside coupled with its synthetic accessibility indicate it is much the preferred drug for incorporation into rational new artemisinin combination therapies.

scholarly journals Evolution of Network Biomarkers from Early to Late Stage Bladder Cancer Samples

2014 ◽  
Vol 2014 ◽  
pp. 1-23 ◽  
Author(s):  
Yung-Hao Wong ◽  
Cheng-Wei Li ◽  
Bor-Sen Chen
Keyword(s):  
Bladder Cancer ◽  
Late Stage ◽  
Early Stage ◽  
Network Structures ◽  
Protein Protein Interaction ◽  
Ppi Networks ◽  
Network Biomarkers ◽  
Two Stages

We use a systems biology approach to construct protein-protein interaction networks (PPINs) for early and late stage bladder cancer. By comparing the networks of these two stages, we find that both networks showed very significantly different mechanisms. To obtain the differential network structures between cancer and noncancer PPINs, we constructed cancer PPIN and noncancer PPIN network structures for the two bladder cancer stages using microarray data from cancer cells and their adjacent noncancer cells, respectively. With their carcinogenesis relevance values (CRVs), we identified 152 and 50 significant proteins and their PPI networks (network markers) for early and late stage bladder cancer by statistical assessment. To investigate the evolution of network biomarkers in the carcinogenesis process, primary pathway analysis showed that the significant pathways of early stage bladder cancer are related to ordinary cancer mechanisms, while the ribosome pathway and spliceosome pathway are most important for late stage bladder cancer. Their only intersection is the ubiquitin mediated proteolysis pathway in the whole stage of bladder cancer. The evolution of network biomarkers from early to late stage can reveal the carcinogenesis of bladder cancer. The findings in this study are new clues specific to this study and give us a direction for targeted cancer therapy, and it should be validated in vivo or in vitro in the future.

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