In a multicellular organism, each cell grows and then eventually dies. It is essential for the survival and growth of an organism that older cells are replaced with new cells via highly controlled mechanism of cell death that occurs mainly in two ways. Cells are either exposed to serious injury or unfavorable hazardous environment that culminates in cell death or in other cases, the cell undergoes planned and controlled process of disintegration that is initiated from within. There are two different processes through which cell death can occur; one is necrosis and the other is apoptosis. Here is a brief overview of necrosis vs. apoptosis.
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Necrosis |
Apoptosis |
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A process of unplanned or premature cell death. |
A planned or programmed cell death that elicits by healthy processes within the body. |
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Necrosis occurs in response to a serious injury, infection or persistent exposure to toxins. |
Natural process. |
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Necrosis has damaging and unfavorable effects on the body. |
Effects of apoptosis are normally beneficial to the body unless the process is uncontrolled. |
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Necrosis is characterized by inflammation, gangrene and poor blood flow towards the affected area. |
There are no pronounced symptoms of apoptosis. |
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It is caused due to various bacterial and fungal infections, presence of certain antigen and antibody along with fibrins. |
Apoptosis is part of normal cell cycle |
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Necrosis causes membrane destruction leading to hypoxia, as a result ATP depletion and metabolic collapse occurs, resulting in the swelling and rupturing of cell, ultimately leading to inflammation in the tissues and cells. |
Chain of events leading to apoptosis include blobbing of cell membrane followed by the cell shrinkage, fragmentation of nucleus, chromatin condensation, breaking of chromosomal DNA and formation of an apoptotic body, which is then engulfed by white blood cells. |
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Must be treated immediately because if not treated, it may lead to life threatening complications. |
Doesn't require any treatment unless too many or very few cell death occurs. |
Necrosis vs. Apoptosis: Definition
Necrosis
Necrosis is a cell death process which occurs due to exposure of cells to hazardous and unfavorable conditions resulting in cellular damage and loss of functionality; ultimately leading to death of cells. It is unplanned or undesired cell death process.
Apoptosis
Apoptosis is a programmed cell death. It is a part of normal cell cycle in which old cells die and are replaced by new ones. It is a continuation of cell multiplication process (mitosis). Each cell has a specific life span after which they die and new cells are formed. For example, red blood cells have life span of 120 days after which they die and new red blood cells are formed.
Necrosis vs. Apoptosis: Causes and Presentation
Necrosis
Necrosis is a pathological condition which occurs in response to cell exposure to hazardous toxins or an antigen such as bacteria or fungus or any condition which has detrimental effect on cell structure and its functions. Necrosis occurs as a result of body's immune system response, which leads to inflammatory reactions, accumulation of cellular debris and ultimately cell death.
Apoptosis
Apoptosis is necessary for normal functioning of body as it keeps a balance in number of cells in an organism because cells continue to multiply and if there is only replication of cell without death of old ones, it will lead to tumor or cancer formation. On the other hand, if too many cells die, it will lead to diseases like AIDS, heart diseases and liver diseases. Therefore, apoptosis is a sign of healthy and normal cell functioning. And if apoptosis is not proceeded normally then it is a matter of worry as it indicates a disease condition.
Necrosis vs. Apoptosis: Treatments
In comparison between necrosis and apoptosis, both are treated in very different ways, because one is abnormal and undesired process while other (apoptosis) is usually considered a normal process.
Necrosis
- NSAIDs and Antibiotics
As a first line treatment, NSAIDs and antibiotics are given to treat inflammation and infections, respectively. In worse conditions, immunosuppressants are given to treat the inflammatory process.
- Removal of Dead Tissues
Debridement refers to the process of removing the dead tissues. This can be done in different ways depending upon the condition of necrotizing mass. In simple cases, it involves cleaning of the affected area but severe cases may require amputations. Sometimes maggot debridement therapy is also acquired in which maggots (fly larvae) are used to remove the necrotized cells from the affected area.
- Antioxidants
Sometimes necrosis occurs due to ischemia i.e. inadequate blood supply to an organ. In this case, antioxidants are given.
Apoptosis
The activation mechanisms and cascades involved in the process of apoptosis are not completely understood yet. Better understanding of apoptosis may allow more targeted treatments with efficacy and effectiveness. Since clinical findings on apoptosis mechanisms will have a direct application in the auto immune diseases such as cancers, Parkinson's and many other diseases (in which cure is still questionable); extensive and advanced research studies needs to be done.
In cases where apoptosis is causing too many uncontrolled cell deaths, inhibition of caspase triggers is required (or minimization of external triggers which are provoking cell death). But for cancers, there is an opposite scenario. Apoptosis is required to be introduced in tumor or cancer cells in order to make them more susceptible to radiations and cytotoxic drugs. A new treatment to ignite apoptosis in cancer cells is use of a generic compound called dichloroacetic acid (DCA), which has proven to be highly effective.