MONITORING OF GENE EXPRESSION IN DIFFERENTIATION OF EMBRYOID BODIES FROM CYNOMOLGUS MONKEY EMBRYONIC STEM CELLS IN THE PRESENCE OF BISPHENOL A

Molecular Basis of the Beneficial Actions of Resveratrol

Resveratrol modulates the transcription factor NF-κB, cytochrome P450 isoenzyme CYP1A1, expression and activity of cyclooxygenase (COX) enzymes, Fas/Fas ligand mediated apoptosis, p53, mTOR and cyclins and various phospho-diesterases resulting in an increase in cytosolic cAMP levels. Cyclic AMP, in turn, activates Epac1/CaMKKβ/AMPK/SIRT1/PGC-1α pathway that facilitates increased oxidation of fatty acids, mitochondrial respiration and their biogenesis and gluconeogenesis. Resveratrol triggers apoptosis of activated T cells and suppresses tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17) and other pro-inflammatory molecules and inhibits expression of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) that may explain its anti-inflammatory actions. Polyunsaturated fatty acids (PUFAs) and their anti-inflammatory metabolites lipoxin A4, resolvins, protectins and maresins have a significant role in obesity, type 2 diabetes mellitus (T2DM), metabolic syndrome and cancer. We observed that PUFAs (especially arachidonic acid, AA) and BDNF (brain-derived neurotrophic factor) protect against the cytotoxic actions of alloxan, streptozotocin, benzo(a)pyrene (BP) and doxorubicin. Thus, there is an overlap in the beneficial actions of resveratrol, PUFAs and BDNF suggesting that these molecules may interact and augment synthesis and action of each other. This is supported by the observation that resveratrol and PUFAs modulate gut microbiota and influence stem cell proliferation and differentiation. Since resveratrol is not easily absorbed from the gut it is likely that it may act on endocannabinoid and light, odor, and taste receptors located in the gut, which, in turn, convey their messages to the various organs via vagus nerve.

Both BMP4 and serum have significant roles in differentiation of embryonic stem cells to primitive and definitive endoderm

Differentiation of embryonic stem (ES) cells is a heterogeneous process which is influenced by different parameters, including growth and differentiation factors. The aim of the present study was to investigate the effect of bone morphogenetic protein-4 (BMP4) signaling on differentiation of mouse ES cells to endodermal lineages. For this purpose, differentiation of the ES cells was induced by embryoid body (EB) formation through hanging drop method. During the suspension stage, EBs were treated with BMP4 in a medium containing either fetal bovine serum (FBS) or knockout serum replacement (KoSR). After plating, EBs showed differentiation to a heterogeneous population of specialized cell types. Two weeks after plating, all the experimental groups expressed three germ layer markers and some primitive and definitive endoderm-specific genes. Quantitative real-time PCR analysis showed higher expression levels of Sox17, Pdx1, Cdx2 and Villin mRNAs in the KoSR plus BMP4 condition and higher Gata4 and Afp expression levels in the FBS plus BMP4 condition. Formation of visceral endoderm and derivatives of definitive endoderm was detected in the BMP4 treated EBs. In conclusion, we demonstrated that both BMP4 signaling and serum composition have significant roles in differentiation of mouse ES cells towards endodermal lineages.

Connexin expression and gap-junctional intercellular communication in ES cells and iPS cells

Pluripotent stem cells, i.e., embryonic stem (ES) and induced pluripotent stem (iPS) cells, can indefinitely proliferate without commitment and differentiate into all cell lineages. ES cells are derived from the inner cell mass of the preimplantation blastocyst, whereas iPS cells are generated from somatic cells by overexpression of a few transcription factors. Many studies have demonstrated that mouse and human iPS cells are highly similar but not identical to their respective ES cell counterparts. The potential to generate basically any differentiated cell types from these cells offers the possibility to establish new models of mammalian development and to create new sources of cells for regenerative medicine. ES cells and iPS cells also provide useful models to study connexin expression and gap-junctional intercellular communication (GJIC) during cell differentiation and reprogramming. In 1996, we reported connexin expression and GJIC in mouse ES cells. Because a substantial number of papers on these subjects have been published since our report, this Mini Review summarizes currently available data on connexin expression and GJIC in ES cells and iPS cells during undifferentiated state, differentiation, and reprogramming.

Effects of bisphenol-A and other endocrine disruptors compared with abnormalities of schizophrenia: an endocrine-disruption theory of schizophrenia

In recent years, numerous substances have been identified as so-called "endocrine disruptors" because exposure to them results in disruption of normal endocrine function with possible adverse health outcomes. The pathologic and behavioral abnormalities attributed to exposure to endocrine disruptors like bisphenol-A (BPA) have been studied in animals. Mental conditions ranging from cognitive impairment to autism have been linked to BPA exposure by more than one investigation. Concurrent with these developments in BPA research, schizophrenia research has continued to find evidence of possible endocrine or neuroendocrine involvement in the disease. Sufficient information now exists for a comparison of the neurotoxicological and behavioral pathology associated with exposure to BPA and other endocrine disruptors to the abnormalities observed in schizophrenia. This review summarizes these findings and proposes a theory of endocrine disruption, like that observed from BPA exposure, as a pathway of schizophrenia pathogenesis. The review shows similarities exist between the effects of exposure to BPA and other related chemicals with schizophrenia. These similarities can be observed in 11 broad categories of abnormality: physical development, brain anatomy, cellular anatomy, hormone function, neurotransmitters and receptors, proteins and factors, processes and substances, immunology, sexual development, social behaviors or physiological responses, and other behaviors. Some of these similarities are sexually dimorphic and support theories that sexual dimorphisms may be important to schizophrenia pathogenesis. Research recommendations for further elaboration of the theory are proposed.