scholarly journals Oocyte Spontaneous Activation: An Overlooked Cellular Event That Impairs Female Fertility in Mammals

2021 ◽  
Vol 9 ◽  
Author(s):  
Wei Cui
Keyword(s):  
Human Reproduction ◽  
Mouse Strains ◽  
Dromedary Camel ◽  
Rat Strains ◽  
Cellular Event ◽  
Sister Chromatids ◽  
Oocyte Collection ◽  
Spontaneous Activation

In mammals, including humans, mature oocytes are ovulated into the oviduct for fertilization. Normally, these oocytes are arrested at metaphase of the second meiosis (MII), and this arrest can be maintained for a certain period, which is essential for fertilizationin vivoand oocyte manipulationsin vitro, such as assisted reproduction in clinics and nuclear/spindle transfer in laboratories. However, in some species and under certain circumstances, exit from MII occurs spontaneously without any obvious stimulation or morphological signs, which is so-called oocyte spontaneous activation (OSA). This mini-review summarizes two types of OSA. In the first type (e.g., most rat strains), oocytes can maintain MII arrestin vivo, but once removed out, oocytes undergo OSA with sister chromatids separated and eventually scattered in the cytoplasm. Because the stimulation is minimal (oocyte collection itself), this OSA is incomplete and cannot force oocytes into interphase. Notably, once re-activated by sperm or chemicals, those scattered chromatids will form multiple pronuclei (MPN), which may recapitulate certain MPN and aneuploidy cases observed in fertility clinics. The second type of OSA occurs in ovarian oocytes (e.g., certain mouse strains and dromedary camel). Without ovulation or fertilization, these OSA-oocytes can initiate intrafollicular development, but these parthenotes cannot develop to term due to aberrant genomic imprinting. Instead, they either degrade or give rise to ovarian teratomas, which have also been reported in female patients. Last but not the least, genetic models displaying OSA phenotypes and the lessons we can learn from animal OSA for human reproduction are also discussed.

scholarly journals FIZZ1 and Ym as Tools to Discriminate between Differentially Activated Macrophages

2002 ◽  
Vol 9 (3) ◽  
pp. 151-159 ◽  
Author(s):  
Geert Raes ◽  
Wim Noël ◽  
Alain Beschin ◽  
Lea Brys ◽  
Patrick de Baetselier ◽  
...  
Keyword(s):  
Mouse Strains ◽  
Molecular Characteristics ◽  
Activated Macrophages ◽  
Alternatively Activated Macrophages ◽  
Different Populations ◽  
Classically Activated Macrophages ◽  
Macrophage Populations ◽  
Alternatively Activated

Although it is well-established that macrophages can occur in distinct activation states, the molecular characteristics of differentially activated macrophages, and particularly those of alternatively activated macrophages (aaMφ), are still poorly unraveled. Recently, we demonstrated that the expression of FIZZ1 and Ym is induced in aaMφ as compared with classically activated macrophages (caMφ), elicitedin vitroor developedin vivoduring infection withTrypanosoma brucei brucei. In the present study, we analyzed the expression of FIZZ1 and Ym in caMφ and aaMφ elicited duringTrypanosoma congolenseinfection and show that the use of FIZZ1 and Ym for the identification of aaMφ is not limited toT. b. bruceiinfection and is independent of the organ sources from which macrophages are obtained. We also demonstrate that FIZZ1 can be used to discriminate between different populations of aaMφ. Furthermore, we studied the effects of various stimuli, and combinations thereof, on the expression of FIZZ1 and Ym in macrophages from different mouse strains and demonstrate that regulation of the expression of FIZZ1 and Ym in macrophages is not dependent on the mouse strain. Finally, we show that these genes can be used to monitor the macrophage activation status without the need to obtain pure macrophage populations.

scholarly journals A Combined Adjuvant TF–Al Consisting of TFPR1 and Aluminum Hydroxide Augments Strong Humoral and Cellular Immune Responses in Both C57BL/6 and BALB/c Mice

Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1408
Author(s):  
Qiao Li ◽  
Zhihua Liu ◽  
Yi Liu ◽  
Chen Liang ◽  
Jiayi Shu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vaccine Development ◽  
Inbred Mouse ◽  
Effective Vaccine ◽  
Mouse Strains ◽  
Cellular Immune Responses ◽  
Recombinant Hbsag ◽  
Cellular Immune

TFPR1 is a novel adjuvant for protein and peptide antigens, which has been demonstrated in BALB/c mice in our previous studies; however, its adjuvanticity in mice with different genetic backgrounds remains unknown, and its adjuvanticity needs to be improved to fit the requirements for various vaccines. In this study, we first compared the adjuvanticity of TFPR1 in two commonly used inbred mouse strains, BALB/c and C57BL/6 mice, in vitro and in vivo, and demonstrated that TFPR1 activated TLR2 to exert its immune activity in vivo. Next, to prove the feasibility of TFPR1 acting as a major component of combined adjuvants, we prepared a combined adjuvant, TF–Al, by formulating TFPR1 and alum at a certain ratio and compared its adjuvanticity with that of TFPR1 and alum alone using OVA and recombinant HBsAg as model antigens in both BALB/c and C57BL/6 mice. Results showed that TFPR1 acts as an effective vaccine adjuvant in both BALB/c mice and C57BL/6 mice, and further demonstrated the role of TLR2 in the adjuvanticity of TFPR1 in vivo. In addition, we obtained a novel combined adjuvant, TF–Al, based on TFPR1, which can augment antibody and cellular immune responses in mice with different genetic backgrounds, suggesting its promise for vaccine development in the future.

scholarly journals Efficacy of Guanabenz Combination Therapy against Chronic Toxoplasmosis across Multiple Mouse Strains

2020 ◽  
Vol 64 (9) ◽  
Author(s):  
Jennifer Martynowicz ◽  
J. Stone Doggett ◽  
William J. Sullivan
Keyword(s):  
Limit Of Detection ◽  
Acute Infection ◽  
Antagonistic Effect ◽  
Mouse Strains ◽  
Chronic Infections ◽  
Content Type ◽  
Brain Cyst ◽  
The Brain

ABSTRACT Toxoplasma gondii, an obligate intracellular parasite that can cause life-threatening acute disease, differentiates into a quiescent cyst stage to establish lifelong chronic infections in animal hosts, including humans. This tissue cyst reservoir, which can reactivate into an acute infection, is currently refractory to clinically available therapeutics. Recently, we and others have discovered drugs capable of significantly reducing the brain cyst burden in latently infected mice, but not to undetectable levels. In this study, we examined the use of novel combination therapies possessing multiple mechanisms of action in mouse models of latent toxoplasmosis. Our drug regimens included combinations of pyrimethamine, clindamycin, guanabenz, and endochin-like quinolones (ELQs) and were administered to two different mouse strains in an attempt to eradicate brain tissue cysts. We observed mouse strain-dependent effects with these drug treatments: pyrimethamine-guanabenz showed synergistic efficacy in C57BL/6 mice yet did not improve upon guanabenz monotherapy in BALB/c mice. Contrary to promising in vitro results demonstrating toxicity to bradyzoites, we observed an antagonistic effect between guanabenz and ELQ-334 in vivo. While we were unable to completely eliminate the brain cyst burden, we found that a combination treatment with ELQ-334 and pyrimethamine impressively reduced the brain cyst burden by 95% in C57BL/6 mice, which approached the limit of detection. These analyses highlight the importance of evaluating anti-infective drugs in multiple mouse strains and will help inform further preclinical studies of cocktail therapies designed to treat chronic toxoplasmosis.

scholarly journals Early Interactions of Murine Macrophages with Francisella tularensis Map to Mouse Chromosome 19

mBio ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Avner Fink ◽  
Musa A. Hassan ◽  
Nihal A. Okan ◽  
Michal Sheffer ◽  
Ana Camejo ◽  
...  
Keyword(s):  
Francisella Tularensis ◽  
Qtl Analysis ◽  
Genetic Factors ◽  
Mouse Strains ◽  
Published Data ◽  
Chromosome 19 ◽  
Bacterial Counts ◽  
Early Stages

ABSTRACT Differences among individuals in susceptibility to infectious diseases can be modulated by host genetics. Much of the research in this field has aimed to identify loci within the host genome that are associated with these differences. In mice, A/J (AJ) and C57BL/6J (B6) mice show differential susceptibilities to various pathogens, including the intracellular pathogen Francisella tularensis . Because macrophages are the main initial target during F. tularensis infection, we explored early interactions of macrophages from these two mouse strains with F. tularensis as well as the genetic factors underlying these interactions. Our results indicate that bacterial interactions with bone marrow-derived macrophages (BMDMs) during early stages of infection are different in the AJ and B6 strains. During these early stages, bacteria are more numerous in B6 than in AJ macrophages and display differences in trafficking and early transcriptional response within these macrophages. To determine the genetic basis for these differences, we infected BMDMs isolated from recombinant inbred (RI) mice derived from reciprocal crosses between AJ and B6, and we followed early bacterial counts within these macrophages. Quantitative trait locus (QTL) analysis revealed a locus on chromosome 19 that is associated with early differences in bacterial counts in AJ versus B6 macrophages. QTL analysis of published data that measured the differential susceptibilities of the same RI mice to an in vivo challenge with F. tularensis confirmed the F. tularensis susceptibility QTL on chromosome 19. Overall, our results show that early interactions of macrophages with F. tularensis are dependent on the macrophage genetic background. IMPORTANCE Francisella tularensis is a highly pathogenic bacterium with a very low infectious dose in humans. Some mechanisms of bacterial virulence have been elucidated, but the host genetic factors that contribute to host resistance or susceptibility are largely unknown. In this work, we have undertaken a genetic approach to assess what these factors are in mice. Analyzing early interactions of macrophages with the bacteria as well as data on overall susceptibility to infection revealed a locus on chromosome 19 that is associated with both phenotypes. In addition, our work revealed differences in the early macrophage response between macrophages with different genetic backgrounds. Overall, this work suggests some intriguing links between in vitro and in vivo infection models and should aid in further elucidating the genetic circuits behind the host response to Francisella tularensis infection.

159 EFFECT OF 3-ISOBUTYL-1-METHYLXANTHINE (IBMX) ON THE GERMINAL VESICLE STAGE OF PORCINE OOCYTES DURING OOCYTE COLLECTION IN VITRO

2014 ◽  
Vol 26 (1) ◽  
pp. 193
Author(s):  
R. Appeltant ◽  
J. Beek ◽  
D. Maes ◽  
A. Van Soom
Keyword(s):  
Germinal Vesicle ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Cumulus Cells ◽  
Guanosine Monophosphate ◽  
Developmental Competence ◽  
Meiotic Arrest ◽  
Oocyte Collection

When using modern maturation conditions for in vitro maturation, pig oocytes yield ~20% blastocysts only. One problem is that cumulus cells, which are normally connected with the immature oocyte by cellular projections penetrating through the zona pellucida and with the oolemma via gap junctions, are prematurely losing these connections after the cumulus–oocyte complex is removed from the follicle. The oocyte possesses a type 3 phosphodiesterase, which degrades 3′,5′-cyclic adenosine monophosphate (cAMP), and this activity is inhibited by supply of 3′,5′-cyclic guanosine monophosphate (cGMP) to the oocyte via the cumulus cells. Consequently, cAMP levels, which are typically high during early stages of oocyte maturation in vivo, decrease, leading to spontaneous nuclear maturation and oocytes of low developmental competence. Therefore, the maintenance of these cumulus-oocyte connections is important to keep cAMP high and the oocyte under meiotic arrest. One way to prevent this drop in cAMP is using N6, 2′-o-dibutyryladenosine 3′,5′-cyclic monophosphate sodium (dbcAMP) that causes an arrest at germinal vesicle (GV) stage II (Funahashi et al. 1997 Biol. Reprod. 57, 49–53). Another option is collecting the oocytes in a medium containing the phoshodiesterase inhibitor, IBMX. The present study investigated the influence of IBMX on the progression of the GV of the oocyte after collection, just before the start of the maturation procedure. The GV stage was defined according to Sun et al. (2004 Mol. Reprod. Dev. 69, 228–234). In parallel with the findings on dbcAMP, we hypothesised an arrest at GV II by the presence of IBMX during collection. One group of oocytes were collected in HEPES-buffered TALP without IBMX (n = 375) and another group in the same medium containing 0.5 mM IBMX (n = 586). An average incubation time of 140 min was applied in both groups, and 3 replicates were performed. The proportions of oocytes before or at GV II and beyond GV II were compared in both groups using logistic regression analysis. The proportion of oocytes was included as dependent variable and group (IBMX addition or not) as independent variable. Replicate was also included in the model. The proportion of oocytes before or at GV II was not statistically significant between the group without and the group with IBMX (59.2 v. 58.7% respectively; P > 0.05). In conclusion, the use of IBMX during oocyte collection did not influence the state of the germinal vesicle of the oocyte during collection, indicating that IBMX did not cause a meiotic arrest in the oocytes during collecting in vitro.

scholarly journals Development of a new mouse model for coxsackievirus-induced myocarditis by attenuating coxsackievirus B3 virulence in the pancreas

2019 ◽  
Vol 116 (10) ◽  
pp. 1756-1766 ◽  
Author(s):  
Sandra Pinkert ◽  
Markian Pryshliak ◽  
Kathleen Pappritz ◽  
Klaus Knoch ◽  
Ahmet Hazini ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Acute Myocarditis ◽  
Systemic Infection ◽  
Coxsackievirus B3 ◽  
Pancreatic Tissue ◽  
Mouse Strains ◽  
Embryonic Mouse ◽  
Chronic Myocarditis

Abstract Aims The coxsackievirus B3 (CVB3) mouse myocarditis model is the standard model for investigation of virus-induced myocarditis but the pancreas, rather than the heart, is the most susceptible organ in mouse. The aim of this study was to develop a CVB3 mouse myocarditis model in which animals develop myocarditis while attenuating viral infection of the pancreas and the development of severe pancreatitis. Methods and results We developed the recombinant CVB3 variant H3N-375TS by inserting target sites (TS) of miR-375, which is specifically expressed in the pancreas, into the 3ʹUTR of the genome of the pancreo- and cardiotropic CVB3 variant H3. In vitro evaluation showed that H3N-375TS was suppressed in pancreatic miR-375-expressing EndoC-βH1 cells >5 log10, whereas its replication was not suppressed in isolated primary embryonic mouse cardiomyocytes. In vivo, intraperitoneal (i.p.) administration of H3N-375TS to NMRI mice did not result in pancreatic or cardiac infection. In contrast, intravenous (i.v.) administration of H3N-375TS to NMRI and Balb/C mice resulted in myocardial infection and acute and chronic myocarditis, whereas the virus was not detected in the pancreas and the pancreatic tissue was not damaged. Acute myocarditis was characterized by myocardial injury, inflammation with mononuclear cells, induction of proinflammatory cytokines, and detection of replicating H3N-375TS in the heart. Mice with chronic myocarditis showed myocardial fibrosis and persistence of H3N-375TS genomic RNA but no replicating virus in the heart. Moreover, H3N-375TS infected mice showed distinctly less suffering compared with mice that developed pancreatitis and myocarditis after i.p. or i.v application of control virus. Conclusion In this study, we demonstrate that by use of the miR-375-sensitive CVB3 variant H3N-375TS, CVB3 myocarditis can be established without the animals developing severe systemic infection and pancreatitis. As the H3N-375TS myocarditis model depends on pancreas-attenuated H3N-375TS, it can easily be used in different mouse strains and for various applications.

scholarly journals Genetic neuroscience of mammalian learning and memory

2003 ◽  
Vol 358 (1432) ◽  
pp. 787-795 ◽  
Author(s):  
Susumu Tonegawa ◽  
Kazu Nakazawa ◽  
Matthew A. Wilson
Keyword(s):  
Cell Types ◽  
Genetically Engineered ◽  
Mouse Strains ◽  
Cellular Mechanisms ◽  
Genetic Manipulations ◽  
Adult Mice ◽  
Multiple Levels ◽  
Primary Research Interest

Our primary research interest is to understand the molecular and cellular mechanisms on neuronal circuitry underlying the acquisition, consolidation and retrieval of hippocampus-dependent memory in rodents. We study these problems by producing genetically engineered (i.e. spatially targeted and/or temporally restricted) mice and analysing these mice by multifaceted methods including molecular and cellular biology, in vitro and in vivo physiology and behavioural studies. We attempt to identify deficits at each of the multiple levels of complexity in specific brain areas or cell types and deduce those deficits that underlie specific learning or memory. We will review our recent studies on the acquisition, consolidation and recall of memories that have been conducted with mouse strains in which genetic manipulations were targeted to specific types of cells in the hippocampus or forebrain of young adult mice.

Phosphorylation of the phosphatase PTPROt at Tyr399is a molecular switch that controls osteoclast activity and bone mass in vivo

2019 ◽  
Vol 12 (563) ◽  
pp. eaau0240 ◽  
Author(s):  
Lee Roth ◽  
Jean Wakim ◽  
Elad Wasserman ◽  
Moran Shalev ◽  
Esther Arman ◽  
...  
Keyword(s):  
Bone Mass ◽  
Cultured Cells ◽  
Phosphorylation Site ◽  
Molecular Switch ◽  
Receptor Type ◽  
Mouse Strains ◽  
Bone Homeostasis ◽  
Osteoclast Activity

Bone resorption by osteoclasts is essential for bone homeostasis. The kinase Src promotes osteoclast activity and is activated in osteoclasts by the receptor-type tyrosine phosphatase PTPROt. In other contexts, however, PTPROt can inhibit Src activity. Through in vivo and in vitro experiments, we show that PTPROt is bifunctional and can dephosphorylate Src both at its inhibitory residue Tyr527and its activating residue Tyr416. Whereas wild-type and PTPROt knockout mice exhibited similar bone masses, mice in which a putative C-terminal phosphorylation site, Tyr399, in endogenous PTPROt was replaced with phenylalanine had increased bone mass and reduced osteoclast activity. Osteoclasts from the knock-in mice also showed reduced Src activity. Experiments in cultured cells and in osteoclasts derived from both mouse strains demonstrated that the absence of phosphorylation at Tyr399caused PTPROt to dephosphorylate Src at the activating site pTyr416. In contrast, phosphorylation of PTPROt at Tyr399enabled PTPROt to recruit Src through Grb2 and to dephosphorylate Src at the inhibitory site Tyr527, thus stimulating Src activity. We conclude that reversible phosphorylation of PTPROt at Tyr399is a molecular switch that selects between its opposing activities toward Src and maintains a coherent signaling output, and that blocking this phosphorylation event can induce physiological effects in vivo. Because most receptor-type tyrosine phosphatases contain potential phosphorylation sites at their C termini, we propose that preventing phosphorylation at these sites or its consequences may offer an alternative to inhibiting their catalytic activity to achieve therapeutic benefit.

Adaptation of a Xenograft AML Model to Evaluate Chemotherapeutic Efficacy In Vivo

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3304-3304 ◽  
Author(s):  
Mark Wunderlich ◽  
Fu-Sheng Chou ◽  
Mahesh Shrestha ◽  
Benjamin Mizukawa ◽  
James C. Mulloy
Keyword(s):  
Blood Cell ◽  
Treatment Period ◽  
Conflicts Of Interest ◽  
Residual Disease ◽  
Synergistic Effects ◽  
Day Treatment ◽  
Chemotherapeutic Agents ◽  
Mouse Strains

Abstract Abstract 3304 Although significant progress has been made in the treatment of leukemia, relapse continues to be a major problem, particularly in acute myeloid leukemia (AML). The prognosis for relapsed leukemia is poor, indicating an area for potential improvements. However, animal models to study the response of human AML to chemotherapeutics and subsequent relapse are lacking. Recently we developed an improved NOD/SCID mouse with IL2RG knockout and transgenic expression of myelo-supportive cytokines SCF, GM-CSF, and IL-3 (the NSGS mouse). This mouse is remarkable in its ability to accept human AML grafts more efficiently than all other available strains. When coupled with in vitro derived AML cells, the NSGS mouse allows for a more predictable AML model with shorter latency and smaller range of death than in other mouse strains, including NSG mice. Importantly, very low numbers of cells reliably generate fatal AML in roughly 40 days, even in non-irradiated NSGS mice, allowing for rapid experimental conclusions and reduced toxicity. With the benefits of these unique tools, we sought to develop a model system to evaluate the efficacy of chemotherapeutic agents on human AML cells in vivo. Engrafted mice received a chemotherapy regimen over a 5-day treatment period consisting of a daily dose of cytarabine with simultaneous injection of doxorubicin during the first three days. Treated mice experienced striking weight loss during the treatment period with a nadir at days 8–10 post-treatment. Mice recovered body weight within 3 weeks. Serial complete blood counts indicated a rapid transient drop in total white blood cell and neutrophil counts and a delayed transient drop in red blood cell and platelet numbers, reminiscent of the effects observed in patients undergoing chemotherapy. The drugs successfully targeted the cells of the bone marrow, as evidenced by a profound loss of cellularity in treated mice relative to controls. When mice harboring N-Ras(G12D) positive AML cells were treated at early time points post-transplant, a significant reduction of tumor burden was observed in the BM and PB, with the grafts of treated mice essentially undetectable for weeks after treatment cessation. Nevertheless, treated mice inevitably succumbed to disease, although with a significantly prolonged latency compared to mock treated mice. However, when AML cells containing the FLT3-ITD mutation were used, a shift in disease latency was not reproducibly seen. This data correlates well with patient data showing that FLT3-ITD mutant AML has a worse prognosis than AML samples with N-Ras mutations. Importantly, the reappearance of AML within weeks of treatment affords the opportunity to model drug resistance and relapse, as well as the potential synergistic effects of experimental compounds used in combination with traditional chemotherapy. Additionally, the period following treatment may allow for studies of minimal residual disease as well as the testing of potential maintenance therapies. Finally, this approach permits a detailed analysis of the critical few cancer stem cells that remain after induction therapy with the goal of identifying novel compounds capable of targeting these cells. Disclosures: No relevant conflicts of interest to declare.

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