SLE (Systemic lupus erythematosis) is a chronic autoimmune disease characterized by the production of autoantibodies and the deposition of immune complexes, affecting a wide range of organs. A complex interaction of genetics, environmental factors and hormones result in the breakdown of immune tolerance to “self” leading to damage and destruction of multiple organs, such as the skin, joints, kidneys, heart and brain. Both innate and adaptive immune systems are critically involved in the misguided immune response against self-antigens. Dendritic cells, neutrophils, and innate lymphoid cells are important in initiating antigen presentation and propagating inflammation at lymphoid and peripheral tissue sites. Autoantibodies produced by B lymphocytes and immune[..]

P53, the most extensively studied tumor suppressor, is a regulative factor of many processes necessary for the proper functioning of cells, and it corresponds to a number of processes associated with its life and death. The p53 protein regulates the repair of cellular DNA and induces apoptosis when the damage of the gene is too serious and it is impossible to repair. P53 can be activated by DNA damage, hypoxia, or aberrant oncogene expression to promote cell-cycle checkpoints, DNA repair, cellular senescence, and apoptosis (Ref.1 and 2). There are four conserved domains in p53: N-terminal domain, which is required for transcriptional transactivation, a sequence-specific DNA binding domain, a tetramerization domain near the C-terminal end and a C-terminal domain that[..]

Angiogenesis and lymphangiogenesis, the growth of new blood vessels from preexisting ones, are important processes during embryonic development, tissue growth, wound healing, and several pathological conditions. Several molecules are important for angiogenesis, most important being vascular endothelial growth factor (VEGF) family members and their corresponding receptors. VEGF belongs to the PDGF supergene family characterized by 8 conserved cysteines and functions as a homodimer structure. In mammals, the VEGF family consists of five members: VEGFA, VEGFB, VEGFC, VEGFD, and placental growth factor (PIGF). The human VEGF gene (located on chromosome 6) consists of several exons that can be alternatively spliced to encode several protein isoforms including: VEGF121,[..]

The endothelium functions as a semipermeable barrier, regulating tissue fluid homeostasis and transmigration of leukocytes and providing essential nutrients across the vessel wall. Transport of plasma proteins and solutes across the endothelium involves two different routes: one transcellular, via caveolae-mediated vesicular transport, and the other paracellular, through interendothelial junctions. The permeability of the endothelial barrier is an exquisitely regulated process in the resting state and in response to extracellular stimuli and mediators. The migratory properties of leukocytes or WBCs (White Blood Cells) are indispensable to drive immune responses throughout the body. To ensure migration to the proper locations, the trafficking of leukocytes is tightly[..]

The migration of leukocytes or WBCs (White Blood Cells) from the vascular system to sites of pathogenic exposure is a key event in the process of inflammation. The inflammatory reaction enables the organism to defend itself against infectious microbes. The entry of leukocytes into sites of injury or infection requires molecular mechanisms which enable the leukocytes to recognize such sites from within the vasculature and to form contact with the endothelium in order to exit and migrate through the blood vessel wall. Recognition as well as contact formation is mediated by several cell adhesion molecules which act in a sequential manner in concert with regulatory mediators such as the Chemokines. The cell adhesion molecules which are involved in this process belong to[..]

In order to initiate a specific immune response to an infectious agent, the immune system must be able to wade through the sea of molecules that are associated with pathogenic invasion and isolate particular protein products that will sharpen the efforts of host defense. Implicit to this model of counteraction is the processing of an immunogenic peptide epitope (Antigen Processing) and its presentation on the surface of a team of cells, referred to as APCs (Antigen Presenting Cells) (Antigen Presentation). The result of these actions is the induction of a T-Cell response that recruits and engages the other molecular participants of the immune response. Antigen processing and presentation refer to the processes that occur within a cell that result in fragmentation[..]

Hematopoiesis is the process that generates blood cells of all lineages (Ref.1). The process of generation of blood cells begins in the early embryo and continues throughout life. Every day, billions of new blood cells are produced in the body, each one derived from a HSC (Hematopoietic Stem Cell). Because most mature blood stem cells have a limited life span, the ability of HSCs to perpetuate themselves through self-renewal and generate new blood cells for the lifetime of an organism is critical to sustaining life. Hematopoietic stem cells are classified into long-term, short-term and Multipotent progenitors, based on the extent of their self-renewal abilities. A key problem in Hematopoietic stem cell biology is how HSC self-renewal is regulated. Signaling cascades[..]

Hematopoietic Stem Cells (HSCs) have the property of self-renewal and through cell division and differentiation, form populations of progenitor cells which are committed to the main marrow cell lines; Erythroid, Granulocytic and Monocytic, Megakaryocytic and Lymphocytic. The earlier progenitor cells are multipotent but, as division and differentiation proceed, later progenitors are formed that are committed to three, two or one cell line (Ref.1 & 2). In the strictest sense depending on potency (i.e., the capacity to differentiate into specialized cell types) stem cells are either Totipotent or Pluripotent. Totipotent cells differentiate into embryonic and extraembryonic cell types, whereas, pluripotent cells are defined as the descendants of totipotent cells which[..]

HSV1 (Herpes Simplex Virus Type-1) is a member of the Herpes group of viruses, the Herpesviridiae, which includes the important human pathogens HSV2, CMV (Cytomegalovirus), Varicella zoster Virus, EBV (Epstein-Barr Virus), HSV6 and 7, and Kaposi's associated Herpes virus, HHV8 (Human Herpesvirus-8). Of these, HSV1 has been the most extensively studied. Human is the only natural host to HSV. The virus is spread by contact and the usual site for the implantation is skin or mucous membrane. Following an initial infection in epithelial cells, the virus spreads to neurons of sensory ganglia, where it becomes latent. The virus emerges sporadically from latency, causing recurrent mucocutaneous lesions. Reactivation of the latent genomes upon stress can lead to re-infection of[..]

Plants have pores, Stomata, on their leaf surfaces that allow CO2 (Carbon Dioxide) in for photosynthesis and through which water evaporates. The specific cells that border and define these pores are Guard Cells. Guard Cells literally guard the size of the pore by alternately swelling, which opens the pore, or shrinking, which closes the pore. Plants must respond to a variety of environmental cues and regulate their Stomata accordingly so that enough CO2 gets in, but not so much water escapes that the plant dries out. This balance between opening and closure of Stomata is essential in determining a plant’s survival and how much it will grow and yield. The swelling and shrinking of Guard Cells occurs through the coordinated movement of water and Ions across the[..]

A blister (bulla) is a bubble of fluid that forms beneath a thin layer of dead skin. The fluid is a mixture of water and proteins that oozes from injured tissue. Blisters most commonly form in response to a specific injury, such as a burn or irritation, and usually involve only the topmost layers of skin. These blisters heal quickly, usually without leaving a scar. Blisters that develop as part of a systemic (bodywide) disease may start in the deeper layers of the skin and cover widespread areas. These blisters heal more slowly and may leave scars. Blistering disease is widely divided in to two catagories: Autoimmune blistering disease and inherited blistering disease. Autoimmune blistering diseases are a group of disorders in which the body mistakenly attacks healthy[..]

The Proper functioning of a cell requires careful control of the levels of important structural proteins, enzymes, and regulatory proteins. Protein molecules are continuously synthesised and degraded in all living organisms. The concentration of individual cellular proteins is determined by a balance between the rates of synthesis and degradation, which in turn are controlled by a series of regulated biochemical mechanisms. Differences in the rates of protein synthesis and breakdown result in cellular and tissue atrophy (loss of proteins from cells) and hypertrophy (increase in protein content of cells). Precise control of protein turnover is, therefore, essential to cellular survival. The only way that cells can reduce the excessive level of a particular protein is by[..]