scholarly journals Dynamic changes in leptin distribution in the progression from ovum to blastocyst of the pre-implantation mouse embryo

Reproduction ◽  
2011 ◽  
Vol 141 (6) ◽  
pp. 767-777 ◽  
Author(s):  
Laura C Schulz ◽  
R Michael Roberts

The hormone leptin, which is primarily produced by adipose tissue, is a critical permissive factor for multiple reproductive events in the mouse, including implantation. In the CD1 strain, maternally derived leptin from the oocyte becomes differentially distributed among the blastomeres of pre-implantation embryos to create a polarized pattern, a feature consistent with a model of development in which blastomeres are biased toward a particular fate as early as the two-cell stage. In this study, we have confirmed that embryonic leptin is of maternal origin and re-examined leptin distribution in two distinct strains in which embryos were derived after either normal ovulation or superovulation. A polarized pattern of leptin distribution was found in the majority of both CD1 and CF1 embryos (79.1 and 76.9% respectively) collected following superovulation but was reduced, particularly in CF1 embryos (29.8%; P<0.0001), after natural ovulation. The difference in leptin asymmetries in the CF1 strain arose between ovulation and the first cleavage division and was not affected by removal of the zona pellucida. The presence or absence of leptin polarization was not linked to differences in the ability of embryos to normally develop to blastocyst. In the early blastocyst, leptin was confined subcortically to trophectoderm, but on blastocoel expansion, it was lost from the cells. Throughout development, leptin co-localized with LRP2, a multi-ligand transport protein, and its patterning resembled that noted for the maternal-effect proteins OOEP, NLRP5, and PADI6, suggesting that it is a component of the subcortical maternal complex with as yet unknown significance in pre-implantation development.

Author(s):  
A.E. Sutherland ◽  
P.G. Calarco ◽  
C.H. Damsky

Cell-extracellular matrix (ECM) interactions mediated by the integrin family of receptors are critical for morphogenesis and may also play a regulatory role in differentiation during early development. We have examined the onset of expression of individual integrin subunit proteins in the early mouse embryo, and their roles in early morphogenetic events. As detected by immunoprecipitation, the α6, αV, β1, and β3 subunits are detected as early as the 4-cell stage, α5 at the hatched blastocyst stage and αl and α3 following blastocyst attachment. We tested the role of these integrins in the attachment and migratory activity of two cell populations of the early mouse embryo: the trophoblast giant cells, which invade the uterine stroma and ultimately contribute to the chorio-allantoic placenta, and the parietal endoderm, which migrates over the inner surface of the trophoblast and ultimately forms Reichert's membrane and the parietal yolk sac. Experiments were done in serum-free medium on substrates coated with laminin (Ln) and fibronectin (Fn). Trophoblast outgrowth occurs on Ln and its E8 fragment (long arm), but not on the E1’ fragment (cross region) (Figs. 1, 2 ). This outgrowth is inhibited by anti-E8, anti-Ln, and by the anti-β1 family antiserum anti-ECMR, but not by anti-αV or the function-perturbing GoH3 antibody that recognizes the α6/β1 integrin, a major Ln (E8) receptor. This suggests that trophoblast outgrowth on Ln or E8 is mediated by a different β1 integrin such as α3/β1. Early stages of trophoblast outgrowth (up to 48 hours) on Fn are inhibited by anti-Fn and by function-perturbing anti-αV antibodies, whereas at later times outgrowth becomes insensitive to anti-αV but remains sensitive to the anti-β1 family antiserum anti-ECMr, indicating that trophoblast cells modulate their interaction with Fn during outgrowth. Trophoblast outgrowth on vitronectin (Vn) is sensitive to anti-αV antibodies throughout the 5-day period examined.


Children ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 288
Author(s):  
Wojciech Rusek ◽  
Joanna Baran ◽  
Justyna Leszczak ◽  
Marzena Adamczyk ◽  
Rafał Baran ◽  
...  

The main goal of our study was to determine how the age of children, puberty and anthropometric parameters affect the formation of body composition and faulty body posture development in children. The secondary goal was to determine in which body segments abnormalities most often occur and how gender differentiates the occurrence of adverse changes in children’s body posture and body composition during puberty. The study group consisted of 464 schoolchildren aged from 6–16. Body posture was assessed with the Zebris system. The composition of the body mass was tested with Tanita MC 780 MA body mass analyzer and the body height was measured using a portable stadiometer PORTSTAND 210. The participants were further divided due to the age of puberty. Tanner division was adopted. The cut-off age for girls is ≥10 years and for boys it is ≥12 years. The analyses applied descriptive statistics, the Pearson correlation, stepwise regression analysis and the t-test. The accepted level of significance was p < 0.05. The pelvic obliquity was lower in older children (beta = −0.15). We also see that age played a significant role in the difference in the height of the right pelvis (beta = −0.28), and the difference in the height of the right shoulder (beta = 0.23). Regression analysis showed that the content of adipose tissue (FAT%) increased with body mass index (BMI) and decreased with increasing weight, age, and height. Moreover, the FAT% was lower in boys than in girls (beta negative equal to −0.39). It turned out that older children (puberty), had greater asymmetry in the right shoulder blade (p < 0.001) and right shoulder (p = 0.003). On the other hand, younger children (who were still before puberty) had greater anomalies in the left trunk inclination (p = 0.048) as well as in the pelvic obliquity (p = 0.008). Girls in puberty were characterized by greater asymmetry on the right side, including the shoulders (p = 0.001), the scapula (p = 0.001) and the pelvis (p < 0.001). In boys, the problem related only to the asymmetry of the shoulder blades (p < 0.001). Girls were characterized by a greater increase in adipose tissue and boys by muscle tissue. Significant differences also appeared in the body posture of the examined children. Greater asymmetry within scapulas and shoulders were seen in children during puberty. Therefore, a growing child should be closely monitored to protect them from the adverse consequences of poor posture or excessive accumulation of adipose tissue in the body.


2016 ◽  
Vol 141 ◽  
pp. 40-50 ◽  
Author(s):  
Monika Humięcka ◽  
Magdalena Krupa ◽  
Maria M. Guzewska ◽  
Marek Maleszewski ◽  
Aneta Suwińska

Development ◽  
1995 ◽  
Vol 121 (1) ◽  
pp. 113-122 ◽  
Author(s):  
E. Christians ◽  
E. Campion ◽  
E.M. Thompson ◽  
J.P. Renard

Activation of the mouse embryonic genome at the 2-cell stage is characterized by the synthesis of several alpha-amanitin-sensitive polypeptides, some of which belong to the multigenic hsp 70 family. In the present work we show that a member of this family, the HSP 70.1 gene, is highly transcribed at the onset of zygotic genome activation. Transcription of this gene began as early as the 1-cell stage. Expression of the gene continued through the early 2-cell stage but was repressed before the completion of the second round of DNA replication. During this period we observed that the level of transcription was modulated by in vitro culture conditions. The coincidence of repression of HSP70.1 transcription with the second round of DNA replication was not found for other transcription-dependent polypeptides synthesized at the 2-cell stage.


Development ◽  
1982 ◽  
Vol 70 (1) ◽  
pp. 133-152
Author(s):  
Susan J. Kimber ◽  
M. Azim ◽  
H. Surani ◽  
Sheila C. Barton

Whole 8-cell morulae can be aggregated with isolated inner cell masses from blastocysts. On examining semithin light microscope sections of such aggregates we found that cells of the morula changed shape and spread over the surface of the ICM, thus translocating it to the inside of the aggregate. Using single cells from 8-cell embryos in combination with single cells from other stage embryos or isolated ICMs we show that 1/8 blastomeres spread over other cells providing a suitably adhesive surface. The incidence of spreading is high with inner cells from 16-cell embryos (56 %) and 32-cell embryos (62%) and isolated inner cell masses (64%). In contrast, the incidence of spreading of 1/8 blastomeres is low over outer cells from 16-cell embryos (26%) and 32-cell embryos (13%). Blastomeres from 8-cell embryos do not spread over unfertilized 1-cell eggs, 1/2 or 1/4 cells or trophectoderm cells contaminating isolated ICMs. When 1/8 cells are aggregated in pairs they flatten on one another (equal spreading) as occurs at compaction in whole 8-cell embryos. However, if 1/8 is allowed to divide to 2/16 in culture one of the cells engulfs the other (51-62/ pairs). Based on the ideas of Holtfreter (1943) and Steinberg (1964,1978) these results are interpreted to indicate an increase in adhesiveness at the 8-cell stage as well as cytoskeletal mobilization. Following the 8-cell stage there is an increase in adhesiveness of inside cells while the outside cells decrease in adhesiveness. The difference in adhesiveness between inside and outside cells in late morulae is probably central to the divergent differentiation of (inner) ICM and (outer) trophectoderm cell populations.


2016 ◽  
Vol 17 (5) ◽  
pp. 382-387 ◽  
Author(s):  
Kamalakanth Shenoy ◽  
George Attokaran

ABSTRACT Background Selecting and replacing missing teeth to natural proportions and esthetic preference of a patient in the absence of pre-extraction records is a very challenging task. Although facial analysis and proportions are well discussed in many populations, none exists for the Thrissur, Kerala, population. A prosthodontic rehabilitation for Kerala patients relying on other racial norms may result in dissonant facial proportions. Therefore, the purpose of this study was (1) to evaluate the validity of innercanthal distance as a guide in determining the mesiodistal dimension of six maxillary anterior teeth in a selected Malayalee population in the Thrissur Municipal Corporation area; (2) to check whether innercanthal distance undergoes dynamic changes over time as a result of aging; and (3) to evaluate whether there is a gender difference in the analyzed mean facial and dental proportions in this population. Materials and methods The study was conducted on 1,200 subjects in the Thrissur Municipal Corporation area. From five wards, 240 subjects were selected, out of which 120 were from the 18 to 25 years age group and 120 from the 40 to 50 years age group. Sixty males and females were selected from each group. The innercanthal distance was measured using a Digital Vernier Caliper, and alginate impressions were made to evaluate the size of maxillary anteriors. The data was analyzed statistically. Results The study showed that there is a high statistical significance between the innercanthal distance and the mesiodistal width of six maxillary anterior teeth in females (p < 0.01) and no significance in males. There was also dynamic changes in the innercanthal dimension and the mesiodistal width of maxillary anteriors with increase in age (p < 0.001). The difference in the mean of innercanthal distance between the genders was highly statistically significant, but no significance was found between the genders in the mesiodistal width of maxillary anteriors. Conclusion Within the population evaluated, there was a high statistical significance in females between the innercanthal distance and the mesiodistal width of six maxillary anterior teeth, but not for males. Innercanthal dimension was found to undergo dynamic changes as age increases in both males and females, and it was much higher in males than in females. There was no statistical significance in the comparative evaluation of mesiodistal width of maxillary anteriors of males and females in the study. Clinical significance Teeth selection is a critical step in determining the outcome of successful prosthodontic treatment. No definite guidelines for the selection of maxillary anterior teeth pertaining to the Thrissur, Kerala, population exist. A prosthodontic rehabilitation of Thrissur, Kerala, patients relying on other racial norms will result in dissonant facial proportions. In selecting maxillary anterior teeth, the knowledge of racial norms will help specify certain esthetic and functional modifications in treatment plans, which might be specific to each group. Therefore, there remains an unquestionable need for a scientific and reliable method for maxillary anterior teeth selection, which can be applied on this group of Indian population. How to cite this article Attokaran G, Shenoy K. Correlation between Innercanthal Distance and Mesiodistal Width of Maxillary Anterior Teeth in a Thrissur, Kerala, India, Population. J Contemp Dent Pract 2016;17(5):382-387.


2019 ◽  
Vol 6 (1) ◽  
pp. 101
Author(s):  
Pallavi Panchu ◽  
Biju Bahuleyan ◽  
Rose Babu ◽  
Vineetha Vijayan

Background: Adipose tissue mainly visceral fat is said to be harmful and acts as a harbinger of metabolic disorders. A changing trend is seen in the recent decades with decreasing incidence of metabolic disorders in men even though visceral fat is said to be higher in them. Sex hormones may influence the deposition pattern of adipose tissue. The aim of this study was to observe effects of age on visceral fat and to know if the difference in gender pattern of fat distribution is maintained throughout life or disappears after menopause.Methods: This cross-sectional observational study was conducted in Thrissur on 385 apparently healthy subjects using Omron body composition analyser. Data was analysed using SPSS 20.0 version. The tests employed were NOVA, independent samples t-test.Results: In each age group, men had significantly higher visceral fat than females. As age increased, visceral fat increased significantly in both genders. In each group, except for younger age groups, VF levels were equal in men and women.Conclusions: Visceral fat is higher in men and this difference is seen in all age groups. As age increases, visceral fat levels also increased in men and women. The distribution of visceral fat is such that a greater number of men have high to very high levels at a younger age group, a feature observed in women only in the peri and post-menopausal age. Adoption of an active lifestyle coupled with healthy diet should protect against onset of metabolic disorders.


Development ◽  
1985 ◽  
Vol 89 (1) ◽  
pp. 133-148
Author(s):  
Roger K. W. Smith ◽  
Martin H. Johnson

The effects of aphidicolin, a reversible inhibitor of DNA polymerase alpha, both on replication and on development of the mouse embryo from the 2- and 4-cell stages to the compacted late 8-cell stage have been assessed. The continuous presence of aphidicolin from G1 of the 4-cell stage resulted in inhibition of DNA replication and prevention of division from 4 to 8 cells, but was without effect on the timing or incidence of cell flattening, surface polarization and cytoplasmic polarization. The continuous presence of aphidicolin from G1 of the 2-cell stage resulted in inhibition of DNA replication, division, and polarization. Some slight intercellular flattening in a few embryos did occur. If addition of aphidicolin was delayed by 10 h to early in G2 of the 2-cell stage, further rounds of replication were blocked and some embryos failed to cleave to 4-cells. Nevertheless, almost all embryos showed evidence of flattening and polarization regardless of cell number. In contrast, if aphidicolin was added in G1 of the 2-cell stage and removed after 10 h, the cells showed delayed DNA replication, little evidence of division, and no cell flattening or polarization. We conclude that DNA replication at the 2-cell stage may be essential for the components of compaction studied, but that DNA replication at the 4- and 8-cell stages is not.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
T Rywik ◽  
A Braniewska ◽  
I Kowalik ◽  
M Firczuk ◽  
K Kozar-Kaminska ◽  
...  

Abstract Background The role of endothelial progenitor cells (EPC) in heart transplantation (HT) is not well defined. Thus, the aim of this study was to evaluate prospectively the dynamic changes of circulating EPC levels in relation to post-HT rejection risk. Methods There were 27 HT recipients who had EPC from peripheral blood quantified during 6 months follow-up after HT. Patients were monitored regularly, by right ventricular endomyocardial biopsy assessment, for cellular rejection (ACR) defined as grade ≥2 or an antibody-mediated rejection (AMR) characterized by histopathological changes recorded as AMR1H. The primary end-point was acute rejection, either AMR or ACR. Results ACR and AMR were observed in 7 (25.9%) and 6 (22.2%) subjects respectively. EPC levels, after logarithmic transformation, immediately post-HT were alike regardless of ACR status, however patients with lower EPC were at risk of AMR at 1 month (Table 1). On the other hand patients with a significant reduction of EPC at 1 month post-HT compared with HT were less likely to have either ACR or AMR (p=0.0003). During longer post-HT observation (12 months) patients had similar EPC levels regardless of the rejection events. Dynamic changes in EPC levels are presented in figure. Nonetheless, greater changes in EPC expressed by coefficient of variation were associated with the risk of either AMR or ACR compared to the participants without rejection (mean [lower–upper quartile]) 15 [13–18] vs 8 [5–13]; p=0.02) and (22 [14–26] vs 8 [5–13]; p=0.01) respectively. EPC by rejection – 1st month following HT ACR (+) AMR (+) ACR (−) and AMR (−) p^ p p N=3 (mean± SD) N=4 (mean± SD) N=20 (mean± SD) ACR (+) vs ACR (−) and AMR (−) AMR (+) vs ACR (−) and AMR (−) EPC log HT 5.14±1.55 3.81±1.01 5.30±0.88 0.0325 0.97 0.025 EPC log M1 4.97±0.59 3.69±1.33 4.15±1.29 0.4160 0.55 0.78 Delta EPC log M1-HT -0.17±1.98* −0.12±1.30* −1.15±1.18# 0.2195 0.44 0.32 ACR – acute cellular rejection; AMR or – acute antibody-mediated rejection; EPC log – endothelial progenitor cells after logarithmic transformation; HT – within 24 hours post-transplantation; M1 – at 1-month post-transplantation; Delta EPC log M1-HT – difference in EPC log between M1 and HT. #p=0.0003 for the difference between M1 vs HT; *p=ns for the difference between M1 vs HT; ^pP – for the difference among the groups. Changes in EPC level post-HT Conclusions Early reduction of EPC levels was predictive of a lower risk of ACR or AMR. Greater dynamic changes of EPC during 6 months of observation were associated with a higher risk of rejection suggesting an important role of EPC in the pathological processes post-HT. Thus our findings suggest significant role of EPC post-HT with respect to rejection status. Acknowledgement/Funding Intramural research grant from the Institute of Cardiology


Zygote ◽  
2019 ◽  
Vol 27 (3) ◽  
pp. 173-179
Author(s):  
Jane C. Fenelon ◽  
Baozeng Xu ◽  
Jay M. Baltz

SummaryRecovery from decreased cell volume is accomplished by a regulated increase of intracellular osmolarity. The acute response is activation of inorganic ion transport into the cell, the main effector of which is the Na+/H+ exchanger NHE1. NHE1 is rapidly activated by a cell volume decrease in early embryos, but how this occurs is incompletely understood. Elucidating cell volume-regulatory mechanisms in early embryos is important, as it has been shown that their dysregulation results in preimplantation developmental arrest. The kinase JAK2 has a role in volume-mediated NHE1 activation in at least some cells, including 2-cell stage mouse embryos. However, while 2-cell embryos show partial inhibition of NHE1 when JAK2 activity is blocked, NHE1 activation in 1-cell embryos is JAK2-independent, implying a requirement for additional signalling mechanisms. As focal adhesion kinase (FAK aka PTK2) becomes phosphorylated and activated in some cell types in response to decreased cell volume, we sought to determine whether it was involved in NHE1 activation in the early mouse embryo. FAK activity requires initial autophosphorylation of a tyrosine residue, Y397. However, FAK Y397 phosphorylation levels were not increased in either 1- or 2-cell embryos after cell volume was decreased. Furthermore, the selective FAK inhibitor PF-562271 did not affect NHE1 activation at concentrations that essentially eliminated Y397 phosphorylation. Thus, autophosphorylation of FAK Y397 does not appear to be required for NHE1 activation induced by a decrease in cell volume in early mouse embryos.


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