Table of Contents
What is the meaning Megakaryopoiesis?
Megakaryopoiesis is the process by which bone marrow progenitor cells develop into mature megakaryocytes (MKs), which in turn produce platelets required for normal hemostasis. Over the past decade, the molecular mechanisms that contribute to MK development and differentiation have begun to be elucidated.
What are the hormones in Megakaryopoiesis?
Thrombopoietin (TPO) is the hormone that, with the exception of platelet shedding, regulates all the steps of megakaryopoiesis, from the hematopoietic stem cell to MK maturation.
Why do we need to control Megakaryopoiesis?
As with all proliferative stimuli, checks on TPO signaling and megakaryopoiesis are required to maintain homeostatic balance and prevent the development of thrombocythemia or leukemia. To ensure that signals are appropriately terminated, many positive regulators also induce their own inhibitors.
Why bone marrow is required?
Healthy bone marrow releases blood cells into the bloodstream when they are mature and when required. Without bone marrow, our bodies could not produce the white cells we need to fight infection, the red blood cells we need to carry oxygen, and the platelets we need to stop bleeding.
What are the stages of thrombopoiesis?
(1) A hemocytoblast gives rise to a common myeloid progenitor cell (CMP). (2) The CMP gives rise to CFU-Meg (or CFU-Mega, the colony forming unit that leads to the formation of megakaryocytes). (3) The CFU-Meg develops into a megakaryoblast. (4) The megakaryoblast develops into a promegakaryocyte.
Where is TPO produced?
liver parenchymal cells
TPO is produced primarily in liver parenchymal cells with much smaller amounts being made in the kidney and bone marrow [9,10]. It is synthesized as a 353 amino acid precursor protein with a molecular weight of 36 kDa [2,4,11].
Do platelets develop from megakaryoblasts?
Megakaryocytes. Megakaryocytes give rise to mature platelets, which are essential to thrombosis and hemostasis (Fig. 19.1). Megakaryoblasts are the earliest forms and develop into promegakaryocytes, which contain granules.
How is bone marrow extracted?
The bone marrow aspiration is usually done first. The doctor or nurse makes a small incision in the skin, then inserts a hollow needle through the bone and into the bone marrow. Using a syringe attached to the needle, a sample of the liquid portion of the bone marrow is withdrawn.
Can a person live without bone marrow?
Bone marrow makes the components of your blood that you need to survive. Bone marrow produces red blood cells that carry oxygen, white blood cells that prevent infection and platelets that control bleeding. The absence of bone marrow can be fatal since it’s an essential part of your body.
How does thrombopoiesis occur?
Thrombopoiesis. Platelets are produced during hematopoiesis in a sub-process called thromopoiesis, or production of thrombocytes. Thrombopoiesis occurs from common myeloid progenitor cells in the bone marrow, which differentiate into promegakaryocytes and then into megakaryocytes.
What is thrombopoiesis?
Thrombopoiesis—from thrombos (Gr., clot)—refers to the production of platelets, which are small (2 to 4 µm), round to ovoid, anucleate cells within blood vessels.
What are the three functions of TPO?
Abstract. In hematopoietic stem cells and megakaryocytes, the thrombopoietin (TPO) receptor signals to control proliferation, maturation, and antiapoptosis.
Do platelets produce TPO?
Abstract. Thrombopoietin is produced at a constant rate by the liver and kidney and is removed from the circulation upon binding and subsequent uptake via the Tpo receptor, c-Mpl, expressed by platelets and mega-karyocytes. Apart from uptake, this study shows that platelets can also function as a storage pool for Tpo.
What kind of food is good for bone marrow?
Protein is primarily found in food items like meat, egg, fish, legumes and sauteed vegetables. It is due to this very reason that patients undergoing a bone marrow transplant are recommended to enhance their protein intake. Such patients should take 1.4 to 1.5 grams of protein per kilogram of their body weight.
What is megakaryopoiesis and how does it work?
Megakaryopoiesis is a complex process that involves the commitment of hematopoietic stem cells (HSCs) to the megakaryocyte (MK) lineage, proliferation of the progenitors, MK maturation and terminal differentiation that produces platelets.
What are megakaryocytes?
Megakaryocytes are derived from the hematopoietic stem cell through successive lineage commitment steps, and they undergo a unique maturation process that includes polyploidization, development of an extensive internal demarcation membrane system and finally formation of proplatelet processes.
How many megakaryopoiesis are there in hematopoietic stem cells?
303 20 Megakaryopoiesis and Thr ombopoiesis: An Update on Cytokines and Lineage … hematopoietic stem cells. J Biol Chem 283 ,
How are platelets released from megakaryocytes?
Megakaryocytes release mature platelets in a complex process. Platelets are known to be released from intermediate structures, designated proplatelets, which are long, tubelike extensions of the megakaryocyte cytoplasm.