The double-edged sword: Proteases cathepsins

The state of enzymes in the human body determines the normal physiology or pathology, so all the six classes of enzymes are crucial. 

Proteases, the hydrolases are one of the six classes of enzymes in the human body.

The proteases are several types based on the nucleophilic amino acid or the metal cofactor used

Cathepsins are proteases with serine, cysteine, or aspartic acid residues as the nucleophiles. These enzymes are critical for digestion, coagulation, immune response, adipogenesis, hormone secretion, peptide synthesis, among scores of other functions.

But, in inflammatory state of the body, cathepsin precursors undergo perpetual proteolytic processing and maturation within lysosomes.

These constant switching on drive cathepsins to play devastating roles. They degrade extracellular matrix (ECM) proteins such as collagen and elastin, mediating parasite infection, autoimmune diseases, tumor metastasis, cardiovascular issues, and neural degeneration, among others.  

Dysregulated cathepsins have been linked to arthritis, periodontitis, pancreatitis, macular degeneration, muscular dystrophy, atherosclerosis, obesity, stroke, Alzheimer's disease, schizophrenia, tuberculosis, and Ebola, among others.

Different subtypes of cathepsins are found in different tissues. Cathepsin E is expressed on a broad range of immune cells, cathepsin K on skin fibroblasts, cathepsin L only in the placenta.


Inflammatory state can provoke these double-edged swords to annihilate the key metabolic pathways of human body. So, its important to control inflammation, and tame the hazards of the autophagy tool cathepsins.

For more information, please read: https://pubmed.ncbi.nlm.nih.gov/29885636/

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