Cellular Inflammation Behind Rare Neurodegenerative Condition — Scientists

NEW DELHI — Researchers have found that inflammation in an immune cell may be responsible for very rare genetic conditions known as lysosomal storage diseases (LSDs).

The LSDs affect one in 7,700 live births and while symptoms present themselves in early ages, most children affected by this scenario die a premature, cruel death.

New research by Hospital for Sick Children (SickKids), affiliated with the University of Toronto, and published in Nature Cell Biology shed lights on this condition which has been lounging in the scientific darkrooms for a long time.

Macrophage cells absorb and digest vast amounts of nutrients to help the immune system function properly. Lysosomes are small organelles that help cells break down and recycle nutrients.

When functional, a lysosome can convert big carbohydrates into tiny sugars, which are then used as an energy source. LSDs cause these macrophage lysosomes to swell and fill with debris, a process that involves enlarged lysosomes struggle to avoid breaking apart and spilling their contents, which would kill the cell, explained the study led by Dr Spencer Freeman, a scientist in the Cell Biology programme; Ruiqi Cai, a senior post-doctoral fellow and Ori Scott, a transition clinician scientist in the Cell Biology programme.

To accomplish this, lysosomes establish a channel that transfers sodium out of the lysosomes, followed by water, to keep them smaller. This sends a sign that the lysosome and cell are stressed.

The stressed macrophages subsequently send out a “SOS” signal by releasing a chemical called MCP-1 (monocyte chemoattractant protein 1), which instructs other macrophages.

The findings indicate that inhibiting the sodium channel or the MCP-1 receptor in macrophages may minimise inflammation and tissue damage in LSDs.

The researchers are likely to keep exploring the molecular underpinnings underlying lysosome failure and inflammation, only then it will be easier to identify new therapeutic targets and enhance the quality of life for individuals suffering with LSDs and other associated disorders such as Parkinson’s.