Karuppiah Thilakavathy

A plethora of human pluripotent stem cells

At the early stages of mammalian development, a number of developmentally plastic cells appear that possess the ability to give rise to all of the differentiated cell types normally derived from the three primary germ layers – unique character known as pluripotency. To date, embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) have been shown to be truly pluripotent. However, recent studies have revealed a variety of other cells that demonstrate pluripotentiality, including very small embryonic‐like stem cells (VSELs), amniotic fluid stem cells (AFSCs), marrow‐isolated adult multilineage inducible cells (MIAMI) and multipotent adult precursor cells (MAPCs). This review summarises key features of these six kinds of pluripotent and potentially pluripotent stem cells (ESCs, iPSCs, VSELs, AFSCs, MIAMI and MAPCs) and the evidence for their pluripotency properties.

Mesenchymal stem cells: From stem cells to sarcomas.

Mesenchymal stem cells (MSCs) have garnered vast interests in clinical settings, especially in regenerative medicine due to their unique properties—they are reliably isolated and expanded from various tissue sources; they are able to differentiate into mesodermal tissues such as bones, cartilages, adipose tissues, and muscles; and they have unique immunosuppressive properties. However, there are some concerns pertaining to the role of MSCs in the human body. On one hand, they are crucial component in the regeneration and repair of the human body. On the contrary, they are shown to transform into sarcomas. Although the exact mechanisms are still unknown, many new leads have pointed to the belief that MSCs do play a role in sarcomagenesis. This review focuses on the current updates and findings of the role of MSCs in their transformation process into sarcomas.

Differentially Expressed Proteins in ER + MCF7 and ER - MDA- MB-231 Human Breast Cancer Cells by RhoGDI-α Silencing and Overexpression

BACKGROUND The consequence of Rho GDP dissociation inhibitor alpha (RhoGDIα) activity on migration and invasion of estrogen receptor positive (ER+) and negative (ER-) breast cancer cells has not been studied using the proteomic approach. Changes in expression of RhoGDIα and other proteins interacting directly or indirectly with RhoGDIα in MCF7 and MDA-MB-231, with different metastatic potentials is of particular interest. MATERIALS AND METHODS ER+ MCF7 and ER- MDA-MB-231 cell lines were subjected to two-dimensional electrophoresis (2-DE) and spots of interest were identified by matrix-assisted laser desorption/ionization time of- flight/time- of-flight (MALDI-TOF/TOF) mass spectrometry (MS) analysis after downregulation of RhoGDIα using short interfering RNA (siRNA) and upregulated using GFP-tagged ORF clone of RhoGDIα. RESULTS The results showed a total of 35 proteins that were either up- or down-regulated in these cells. Here we identifed 9 and 15 proteins differentially expressed with silencing of RhoGDIα in MCF-7 and the MDA-MB-231 cells, respectively. In addition, 10 proteins were differentially expressed in the upregulation of RhoGDIα in MCF7, while only one protein was identified in the upregulation of RhoGDIα in MDA-MB-231. Based on the biological functions of these proteins, the results revealed that proteins involved in cell migration are more strongly altered with RhoGDI-α activity. Although several of these proteins have been previously indicated in tumorigenesis and invasiveness of breast cancer cells, some ohave not been previously reported to be involved in breast cancer migration. Hence, these proteins may serve as useful candidate biomarkers for tumorigenesis and invasiveness of breast cancer cells. CONCLUSIONS Future studies are needed to determine the mechanisms by which these proteins regulate cell migration. The combination of RhoGDIα with other potential biomarkers may be a more promising approach in the inhibition of breast cancer cell migration.

An effective placental cotyledons proteins extraction method for 2D gel electrophoresis

Effective protein extraction is essential especially in producing a well‐resolved proteome on 2D gels. A well‐resolved placental cotyledon proteome, with good reproducibility, have allowed researchers to study the proteins underlying the physiology and pathophysiology of pregnancy. The aim of this study is to determine the best protein extraction protocol for the extraction of protein from placental cotyledons tissues for a two‐dimensional gel electrophoresis (2D‐GE). Based on widely used protein extraction strategies, 12 different extraction methodologies were carefully selected, which included one chemical extraction, two mechanical extraction coupled protein precipitations, and nine chemical extraction coupled protein precipitations. Extracted proteins were resolved in a one‐dimensional gel electrophoresis and 2D‐GE; then, it was compared with set criteria: extraction efficacy, protein resolution, reproducibility, and recovery efficiency. Our results revealed that a better profile was obtained by chemical extraction in comparison to mechanical extraction. We further compared chemical extraction coupled protein precipitation methodologies, where the DNase/lithium chloride‐dense sucrose homogenization coupled dichloromethane‐methanol precipitation (DNase/LiCl‐DSH‐D/MPE) method showed good protein extraction efficiency. This, however, was carried out with the best protein resolution and proteome reproducibility on 2D‐gels. DNase/LiCl‐DSH‐D/MPE was efficient in the extraction of proteins from placental cotyledons tissues. In addition, this methodology could hypothetically allow the protein extraction of any tissue that contains highly abundant lipid and glycogen.

Quantitative analysis of fetal DNA in maternal plasma in gestational diabetes mellitus, iron deficiency anemia and gestational hypertension pregnancies.

Abstract Objective: To quantify circulating fetal DNA (fDNA) levels in the second and third trimesters of normal healthy pregnant individuals and pregnant women with the following clinical conditions: gestational diabetes mellitus (GDM), iron deficiency anemia and gestational hypertension (GHT). Methods: The SRY gene located on the Y chromosome was used as a unique fetal marker. The fDNA was extracted from maternal plasma and the SRY gene concentrations were measured by quantitative real-time polymerase chain reaction (PCR) amplification using TaqMan dual labeled probe system. Results: No significant differences were observed in the mean fDNA concentration between normal and GDM pregnancy samples (p > 0.05) and also between normal and anemic pregnancy samples (p > 0.05) in both trimesters, but significant differences were observed between the third trimester normal and GHT pregnancy samples (p = 0.001). GDM and iron deficiency anemia do not affect the levels of fDNA in maternal plasma while GHT significantly elevates the levels of fDNA in maternal plasma. Conclusions: Increased amount of circulating fDNA in maternal plasma could be used for early identification of adverse pregnancies. GDM and anemia do not affect the levels of fDNA in maternal plasma while GHT significantly elevates the levels of fDNA in maternal plasma. Hence, the elevated fDNA values could be used as a potential screening marker in pregnancies complicated with GHT but not with GDM and iron deficiency anemia.

Highly potent stem cells from full-term amniotic fluid: A realistic perspective

Amniotic fluid (AF) is now known to harbor highly potent stem cells, making it an excellent source for cell therapy. However, most of the stem cells isolated are from AF of mid-term pregnancies in which the collection procedure involves an invasive technique termed amniocentesis. This has limited the access in getting the fluid as the technique imposes certain level of risks to the mother as well as to the fetus. Alternatively, getting AF from full-term pregnancies or during deliveries would be a better resolution. Unfortunately, very few studies have isolated stem cells from AF at this stage of gestation, the fluid that is merely discarded. The question remains whether full-term AF harbors stem cells of similar potency as of the stem cells of mid-term AF. Here, we aim to review the prospect of having this type of stem cells by first looking at the origin and contents of AF particularly during different gestation period. We will then discuss the possibility that the AF, at full term, contains a population of highly potent stem cells. These stem cells are distinct from, and probably more potent than the AF mesenchymal stem cells (AF-MSCs) isolated from full-term AF. By comparing the studies on stem cells isolated from mid-term versus full-term AF from various species, we intend to address the prospect of having highly potent amniotic fluid stem cells from AF of full-term pregnancies in human and animals.