By-Dr Vinay Kumar Mehra.
vinay28mehra@yahoo.com
*Animal Biotechnology Centre, ICAR-National Dairy Research Institute, Karnal-13200, Haryana
Domestic animals are usually suffering from various skin problems, some are easy to cure but others are more complicated, which affect the productivity and comfort of the animals and led to economical loss of farmer. So it is very important to cure the skin diseases of the animals as soon as possible to reduce losses. Skin is one of the most vital organ in the body due to its important functions as a protective barrier against various external agents and also serve as a temperature regulator. It is made up of three layers: epidermis, dermis, and hypodermis. An injury or any disorder in the normal structure of the skin, which can lead to loss of conjunction in the body tissue called as wound.
Time is a significant parameter in wound healing and repair and there are several reports which suggested that treatment of skin wound with stem cell reduces the healing time of damaged tissue or wound compare to normal treatment, which provide a promising opportunity for the treatment of skin diseases/ damaged tissue.
The process of dermal wound repair:
Clinically wounds are divided into two groups (i) acute group and (ii) chronic group. Any injury to the skin that occurs suddenly rather than over time, which damaging the integrity of soft tissue is known as acute wound. The wounds, which are caused by various mechanical or environmental damages such as extreme high temperature changes, contact with chemicals, and radiation, resulting in the entrance of the organism into the body and cause infection, knows as chronic wounds. Unlike acute wounds, healing of chronic wounds is slow down due to prolonged pathological inflammation, while the process of treatment is similar in both types.
Wound repair is a complex biological process in the body, which occurring in all tissues and organs. The repair process is depends on the type of injury. Skin wound repair is a highly dynamic process including interaction between epidermal and dermal cells, controlled angiogenesis, the extracellular matrix, and plasma-derived proteins. It consists of three phases: inflammation, proliferation and tissue remodeling. Inflammation is the first stem which occurs soon after tissue damage, and the key feature of this phase is to prevent infection. The inflammatory response starts with the release of cytokines such as platelet-derived growth factor (PDGF), transforming growth factor (TGF-β), fibroblast growth factor (FGF) and epidermal growth factor (EGF). The proliferation stage of tissue repairing begins almost 2–10 days after skin/tissue damage and it is determined through interaction between different cell types. At first, keratinocytes are come to the injured dermis and then the angiogenesis occurs. During angiogenesis, fibroblasts and macrophages replace the fibrin clot.In the final stage (remodeling), fibroblasts and macrophages are transformed into myofibroblasts. This myofibroblasts are classified as contractile cells and play a important role in the closure of the wound. The main objective of the remodeling stage is to extend new epithelium and apoptosis of redundant blood vessels, fibroblasts, and inflammatory cells, resulting in maturation of wound.
What is Stem Cell?
Stem cells are uncommitted, undifferentiated and self-renewable cell types which can give rise to different cell lineages including cartilage, bone, muscle and adipose tissues and many more other cell/tissue types. There are several types of stem cells including embryonic stem cell, induced pluripotent stem cells (iPS), and adult stem cells. Various study have been reported that every organ or tissue in the body contain adult stem cells. Among the different types of adult stem celsl, mesenchymal stem cells (MSCs) and adipose-derived stromal cells (ASCs) play important role to enhance tissue regeneration. The MSCs have the ability to migrate from the bone marrow to an injured site and differentiate into functional skin cell. Furthermore, MSCs secrete soluble factors that regulate cellular responses, angiogenesis formation and tissue remodeling and play a important role in different phases of wound‐healing process including, inflammation, proliferation, contraction and remodeling. Additionally, MSCs have antimicrobial activity which preventing the wound infection. So this therapeutic potential of mesenchymal stem cells makes them an attractive choice for the treatment of chronic wounds. The MSCs can be isolated from various sites such as bone marrow, adipose tissue, amniotic fluid, and dermis and can be used as regenerative medicine. Apart from this MSCs can interact with various immune cells such as natural killer (NK) cells T cells, B cells and macrophages and induce MSC-regulated immune-suppression. The immune-suppression by MSCs is not activated at all times and it is dependent on the type and strength of the inflammatory stimulation.
So systemically injection of MSCs, migrate to various sites of injury in the host. And help in wound healing events such as matrix deposition and blood vessel formation by stimulating increased rate of proliferation, differentiation, and growth factor production such as fibroblast growth factor and vascular endothelial growth factor. So all these properties makes MSCs the best candidate for wound‐healing.
Conclusion:
The skin diseases or wounds in livestock animals reduce the health and productivity of the animals which leads to economical loss of framers. Normal treatment of chronic wounds requires longer time and some time not curable. So using of Mesenchymal stem cells as a regenerative medicine provides a promising area for the treatment of skin diseases in domestic animals
