scholarly journals Microphysiological systems to study microenvironment-cell nucleus interaction: importance of tissue geometry and heterogeneity

2018 ◽  
Vol 2 ◽  
pp. 12-12 ◽  
Author(s):  
Sophie A. Lelièvre ◽  
Shirisha Chittiboyina
Author(s):  
D.L. Spector ◽  
S. Huang ◽  
S. Kaurin

We have been interested in the organization of RNA polymerase II transcription and pre-mRNA splicing within the cell nucleus. Several models have been proposed for the functional organization of RNA within the eukaryotic nucleus and for the relationship of this organization to the distribution of pre-mRNA splicing factors. One model suggests that RNAs which must be spliced are capable of recruiting splicing factors to the sites of transcription from storage and/or reassembly sites. When one examines the organization of splicing factors in the nucleus in comparison to the sites of chromatin it is clear that splicing factors are not localized in coincidence with heterochromatin (Fig. 1). Instead, they are distributed in a speckled pattern which is composed of both perichromatin fibrils and interchromatin granule clusters. The perichromatin fibrils are distributed on the periphery of heterochromatin and on the periphery of interchromatin granule clusters as well as being diffusely distributed throughout the nucleoplasm. These nuclear regions have been previously shown to represent initial sites of incorporation of 3H-uridine.


Author(s):  
David L. Spector ◽  
Robert J. Derby

Studies in our laboratory are involved in evaluating the structural and functional organization of the mammalian cell nucleus. Since several major classes (U1, U2, U4/U6, U5) of small nuclear ribonucleoprotein particles (snRNPs) play a crucial role in the processing of pre-mRNA molecules, we have been interested in the localization of these particles within the cell nucleus. Using pre-embedding immunoperoxidase labeling combined with 3-dimensional reconstruction, we have recently shown that nuclear regions enriched in snRNPs form a reticular network within the nucleoplasm which extends between the nucleolar surface and the nuclear envelope. In the present study we were inte rested in extending these nuclear localizations using cell preparation techniques which avoid slow penetration of fixatives, chemical crosslinking of potential antigens and solvent extraction. CHOC 400 cells were cryofixed using a CF 100 ultra rapid cooling device (LifeCell Corp.). After cryofixation cells were molecular distillation dried, vapor osmicated, in filtra ted in 100% Spurr resin in vacuo and polymerized in molds a t 60°C. Using this procedure we were able to evaluate the distribution of snRNPs in resin embedded cells which had not been chemically fixed, incubated in cryoprotectants or extracted with solvents.


Acta Naturae ◽  
2017 ◽  
Vol 9 (4) ◽  
pp. 42-51
Author(s):  
S. S. Ryabichko ◽  
◽  
A. N. Ibragimov ◽  
L. A. Lebedeva ◽  
E. N. Kozlov ◽  
...  

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Ruswana Anwar ◽  
Muhammad Alif ◽  
Adhi Pribadi

Endometriosis is one of the most common gynecological problem. Cells resulted in chronic inflammation and progressive, proliferative, invasive and even infiltrating an area that resembles the character of the malignancy. Ki-67 is an antigen on the cell nucleus that is found only in actively dividing cells. Expression of Ki-67 are associated with an aggressive tumor and metastasis. This study aims to determine the level of Ki-67 expression correlation with stage and size of the endometriosis cyst. Methods research is observational analytic cross cut method on 56 paraffin blocks of patients who have been diagnosed with endometriosis and had performed a laparotomy or laparoscopic surgery in Dr Hasan Sadikin Hospital. The results showed a significant relationship between the level of expression of Ki-67 with endometriosis cyst size (p <0.001) with a fairly strong relationship (0.55) according to statistics based on criteria Guilford. Moreover the results also showed a significant relationship between the level of expression of Ki-67 with endometriosis stage (p <0.001) with a fairly close relationship (0.564) according to statistics based on criteria Guilford. It can be concluded that the expression of Ki-67 associated with cyst size and stage of endometriosis. Keywords: Ki-67, endometriosis stage, endometriosis cyst


Biosensors ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 110 ◽  
Author(s):  
Erika Ferrari ◽  
Cecilia Palma ◽  
Simone Vesentini ◽  
Paola Occhetta ◽  
Marco Rasponi

Organs-on-chip (OoC), often referred to as microphysiological systems (MPS), are advanced in vitro tools able to replicate essential functions of human organs. Owing to their unprecedented ability to recapitulate key features of the native cellular environments, they represent promising tools for tissue engineering and drug screening applications. The achievement of proper functionalities within OoC is crucial; to this purpose, several parameters (e.g., chemical, physical) need to be assessed. Currently, most approaches rely on off-chip analysis and imaging techniques. However, the urgent demand for continuous, noninvasive, and real-time monitoring of tissue constructs requires the direct integration of biosensors. In this review, we focus on recent strategies to miniaturize and embed biosensing systems into organs-on-chip platforms. Biosensors for monitoring biological models with metabolic activities, models with tissue barrier functions, as well as models with electromechanical properties will be described and critically evaluated. In addition, multisensor integration within multiorgan platforms will be further reviewed and discussed.


Sign in / Sign up

Export Citation Format

Share Document