Stem Cells are undifferentiated cells that can give rise to several lineages of differentiated cell types. They are the founder cells for every organ, tissue and cell in the body. Stem cells are characterized by the ability to self-renew and maintain Pluripotency. These features allow Stem Cells to fulfill their multiple functions, namely to provide enough cells during organogenesis, to control tissue homeostasis and, in addition, to ensure regeneration and repair. ESCs (Embryonic Stem Cells) are derived from the ICM (Inner Cell Mass) of the developing Blastocysts, multicellular structures originating from four (Human) to five (Mouse) cleavages of fertilized oocytes. In Human, the fertilization of an Egg by a Sperm generates a Zygote that thirty hours later begins to[..]

The Rho family of small GTP-binding proteins comprises a group of signaling molecules that are activated by a variety of Growth factors, Cytokines, Adhesion molecules, Hormones, Integrins, G-proteins and other biologically active substances and regulate a wide range of biological processes, including Reorganization of the Actin Cytoskeleton, Transcriptional Regulation, Vesicle Trafficking, Morphogenesis, Neutrophil activation, Phagocytosis and activation of the NADPH Oxidase, Mitogenesis, Apoptosis and Tumorigenesis. The mammalian Rho GTPase family currently consists of three subfamilies, Rho (RhoA, RhoB and RhoC), Rac (Rac1, Rac2 and Rac3) and CDC42 (Cell Division Cycle-42) (CDC42Hs and G25K). The best-characterized family members of Rho Family GTPase are RhoA, Rac1[..]

Epithelia in multicellular organisms constitute the frontier that separates the individual from the environment. Epithelia are sites of exchange as well as barriers, for the transit of ions and molecules from and into the organism. Epithelial cells achieve this by providing cellular borders that cover external and internal surfaces throughout the body. Complexes between adjacent cells include Gap Junctions, Desmosomes, Adherens Junctions (AJs) and Tight Junctions (TJs). Such junctions are quite essential for the modulation of paracellular permeability in various epithelia. Vertebrate epithelial cells exhibit Tight Junctions that lie apical to Adherens Junctions. Tight Junctions have an organizing role in epithelial polarization and establish an apico-lateral barrier to[..]

T cell responses against tumors require the recognition of specific peptides derived from tumor antigens in association with MIC (MHC Class I Molecules) by CD81 T cells expressing TCRs (T Cell Receptors). Such response generates intracellular antigen processing which are highly selective and binds only to some of the numerous polymorphic MHC class I molecules and often-impaired expression of MHC class I on tumor cells. Human gamma delta T cells are MICA (MHC-Class-Ipolypeptide-Related sequence-A) and MICB (MHC-Class-Ipolypeptide-Related sequence-B), which are distantly related to MHC class I but are functionally distinct. These molecules have no role in the presentation of intracellular peptide antigens instead MICA and MICB are closely related and functionally[..]

Embryonic development is the generation of a multicellular organism from a single cell. During this process, tissues and organs are differentiated and positioned at different parts of the organism. In animals, Embryonic development consists of 4 stages: Cleavage, Patterning, Differentiation and Growth. Mammalian Cleavage is strikingly different from most other patterns of Embryonic cell division. The mammalian oocyte is released from the ovary and swept by the fimbriae into the oviduct. The mature oocyte is surrounded by a protective coat of noncellular material (made of extracellular matrix and glycoproteins), called the Zona pellucida. Fertilization occurs in the ampulla of the oviduct, a region close to the ovary. For fertilization to occur, a haploid sperm cell[..]

An Embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination. In Humans, it is called an Embryo from the moment of Fertilization until the end of the 8th week of gestational age, whereafter it is instead called a Fetus. In organisms that reproduce sexually, once a Sperm fertilizes an Egg cell, the result is a cell called the Zygote. In animals, the development of the Zygote into an embryo proceeds through specific recognizable stages of Blastula, Gastrula, and Organogenesis. Little is known about the specific genes that regulate these early events or how interactions among cells or how cellular interactions with other factors in the three-dimensional environment of the[..]

ERK5 (also known as the BMK1 (Big MAP Kinase-1)) is an atypical MAPK that can be activated in vivo by a variety of stimuli, including Serum, Growth factors including EGF (Epidermal Growth Factor), NGF (Nerve Growth Factor) and BDNF (Brain-Derived Neurotrophic Factor), GPCRs (G-Protein Coupled Receptors), Lysophosphatidic Acid, Neurotrophins and Phorbol ester and some Cellular stress such as Oxidative and Osmotic Shock. MAPK (Mitogen Activated Protein Kinase) cascades play important roles in many cellular processes including cell proliferation, differentiation, survival and apoptosis. They are also important for many physiological functions in several systems, including in developmental, immune and neuronal systems. At least 12 isoforms of MAPKs exist in mammalian[..]

Glioblastoma Multiforme (GBM) is biologically aggressive neoplasms which have an elevated, often aberrant, proliferative capacity with a diffuse pattern of brain invasion. It is the most malignant Astrocytic tumor, composed of poorly differentiated neoplastic astrocytes. The World Health Organization (WHO) grading system classifies Gliomas into Grades I-IV based on the degree of malignancy, as determined by histopathological criteria. In the Central Nervous System (CNS), Grade-I Gliomas generally behave in a benign fashion and might even be circumscribed, whereas Grade-II, Grade-III and Grade-IV Gliomas are malignant and diffusely infiltrate throughout the brain. Glioblastoma Multiforme falls under the Grade-IV category. Glioblastoma Multiforme or the WHO Grade-IV[..]

ILK(Integrin-linked kinase) is a key scaffold protein that localizes to focal adhesions, acts as a central component of a heterotrimer (the ILK–PINCH–parvin complex). Since its discovery, ILK has been demonstrated to have an essential role in connecting the cytoplasmic tail of β subunits of integrins to the actin cytoskeleton, and in regulating actin polymerization. Within this pivotal position, ILK has been shown to interact with many intracellular proteins through PINCH or parvin to mediate diverse arrays of biological events,or to mediate cell responses induced by the interaction of integrins with the ECM(extracellular matrix)(Ref.1). Several adaptor proteins with Actin binding properties interact with the C-terminus (COOH-terminus) of ILK.[..]

In response to Retinoic Acid (a metabolite of Vitamin-A (all-trans-Retinol), which affects gene transcription), target genes are regulated by two families of nuclear receptors, the RARs (Retinoic Acid Receptors) and the RXRs (Retinoid X Receptors) that bind as RAR/RXR heterodimers to response elements located in their promoters. The all-trans-Retinoic Acid, the Carboxylic Acid form of Vitamin-A is of biological significance since it is predominant under most physiological situations and explains all of the biological effects of Vitamin-A (Ref.1). Biologically active ligands for the RARs include all-trans-Retinoic Acid, 9-cis-Retinoic Acid among others, yet circulating levels of 9-cis-Retinoic Acid are much lower than those of all-trans-Retinoic Acid and the[..]

Influenza (mostly referred to as “flu”) is a contagious viral infection caused primarily by the influenza virus A or B. It affects mainly the upper respiratory organs (i.e., the nose, throat, bronchi, and infrequently, lungs) but other organs such as the heart, brain, and muscles can be involved. It occurs worldwide and causes considerable morbidity and mortality with pandemic, epidemic, or seasonal patterns. Typical Influenza illness includes fever and respiratory symptoms, such as cough, sore throat, runny or stuffy nose, as well as headache, muscle aches, and often extreme fatigue. Although nausea, vomiting, and diarrhea can sometimes accompany Influenza infection, especially in children, these symptoms are rarely the primary symptoms. Most people[..]

Diabetes mellitus is a chronic disease characterized by high blood glucose levels that requires long-term medical attention both to limit the development of its devastating complications and to manage them when they do occur. The pancreatic Beta-cell and its secretory product insulin are central in the pathophysiology of diabetes. There are two main types of diabetes, Type-I, which is insulin dependent, and Type-II, which is non-insulin dependent. Type-II diabetes is a complex and heterogeneous disease caused by both environmental and genetic factors. It maybe of various forms each of which is characterized by variable degrees of insulin resistance and Beta-cell dysfunction, and which together lead to hyperglycemia. At each end of this spectrum are single gene[..]