The Build Up of Lipofuscin In Lysosomes

Lysosomes are the recycling centers of our cells. They are packed with enzymes(proteins which speed up chemical reactions), with each enzyme "trained" to target weak spots in chemical waste. The enzyme latches onto the chemical structure, like a mutated mitochondria for example, and then twists and tears its molecular joints.

Now, Lipofuscin is any waste product that refuses to break down inside the lysosome. The lysosome simply doesn't have to correct enzymes for the job. Therefore, the lipofuscin accumulates inside of the lysosome and takes up a large amount of room, especially in the lysosomes of long-lived cells, like the heart and brain for example. Since the heart cells never divide; therefore, they don't share the lysosome waste between the two offspring cells.

 The serious damage occurs like this:

Mutilated Low-Density Lipoprotein, LDL cholesterol,which has been damaged by free radicals, tries to deliver membrane materials(that's what cholesterol does) to cells along the arteries. Since the LDL is damaged, its proteins tend to stick together which other LDL's. This is why high-cholesterol is detrimental, since the more cholesterol in your blood, the more contact it has with free radicals, and the more it clogs up your blood stream. When the LDL is in the blood stream, it tries to slip through the blood vessels and head for the cell that is receiving its new membrane. But alas, the LDL never makes it to the cell since it gets caught in the blood vessel. This stuck LDL begins to attract other LDL's, which in turn get stuck as well.

Once a decent-sized plaque of LDL is formed, the immune system sends a phagocyte, known as macrophages, to clean up the mess. Unfortunately, the lysosomes inside the macrophages do not have the correct enzymes to clean up the LDL, and it turns into lipofuscin. The lipofuscin builds up inside the lysosome until it actually explodes and kills the macrophage, which adds to the already accumulating clot.

When this clot occurs near the heart = heart attack. Near the brain = stroke.

Aside from heart attacks and stoke, the build up of lipofuscin in lysosomes is also responsible for Age-Related Macular Degeneration, or vision loss.
Vision is from energy from the light that is reflected off the object, into the lens of our eyes, and is carried through our optic nerve to our visual cortex(back lobe of the brain). A chemical reaction occurs and our vision is produced. Since vision relies on chemically unstable components, issues will arise. A by-product, known as A2E is formed in our cones and rodes, which cannot be broken down by lysosomes and eventually ruins our retinas.