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Updated: May 13, 2026
Quantifying Tissue-Specific Proteostatic Decline in Caenorhabditis elegans
Published on: September 7, 2021
PAK1-deficiency/down-regulation reduces brood size, activates HSP16.2 gene and extends lifespan in Caenorhabditis
Abstract:
There is an increasing evidence that the oncogenic kinase PAK1 is responsible not only for malignant transformation, but also for several other diseases such as inflammatory diseases (asthma and arthritis), infectious diseases including malaria, AIDS, and flu, as well as a series of neuronal diseases/disorders (neurofibromatosis, tuberous sclerosis, Alzheimer's diseases, Huntington's disease, epilepsy, depression, learning deficit, etc.) which often cause premature death. Interestingly, a few natural PAK1-blockers such as curcumin, caffeic acid (CA) and rosmarinic acid (RA) extend the lifespan of the nematode Caenorhabditis elegans or fruit flies. Here, to explore the possibility that C. elegans could provide us with a quick and inexpensive in vivo screening system for a series of more potent but safe (non-toxic) PAK1-blocking therapeutics, we examined the effects of PAK1-deficiency or down-regulation on a few selected functions of this worm, including reproduction, expression of HSP16.2 gene, and lifespan. In short, we found that PAK1 promotes reproduction, whereas it inactivates HSP16.2 gene and shortens lifespan, as do PI-3 kinase (AGE-1), TOR, and insulin-like signalling /ILS (Daf-2) in this worm. These findings not only support the "trade-off" theory on reproduction versus lifespan, but also suggest the possibility that the reduced reproduction (or HSP16.2 gene activation) of this worm could be used as the first indicator of extended lifespan for a quick in vivo screening for PAK1-blockers.
Insights
The oncogenic kinase PAK1 promotes reproduction but shortens lifespan in C. elegans. PAK1 deficiency or inhibition may serve as a biomarker for novel therapeutics targeting diseases linked to PAK1.
Area of Science:
- Molecular Biology
- Genetics
- Aging Research
Background:
- The oncogenic kinase PAK1 is implicated in various diseases, including cancer, inflammation, infectious diseases, and neurological disorders.
- Natural PAK1 inhibitors like curcumin, caffeic acid (CA), and rosmarinic acid (RA) have shown lifespan-extending effects in model organisms.
- Caenorhabditis elegans offers a potential in vivo model for screening PAK1-blocking therapeutics.
Purpose of the Study:
- To investigate the role of PAK1 in C. elegans functions, including reproduction, HSP16.2 gene expression, and lifespan.
- To evaluate C. elegans as a cost-effective in vivo system for identifying potent and safe PAK1 inhibitors.
- To explore the correlation between reproduction, HSP16.2 gene activation, and lifespan extension as indicators for PAK1-blockers.
Main Methods:
- Examined the effects of PAK1 deficiency or down-regulation on C. elegans reproduction, HSP16.2 gene expression, and lifespan.
- Compared PAK1's effects with known aging-related pathways like PI-3 kinase (AGE-1), TOR, and insulin-like signaling (Daf-2).
Main Results:
- PAK1 was found to promote reproduction in C. elegans.
- PAK1 was observed to inactivate the HSP16.2 gene and shorten lifespan.
- These effects align with those of other aging-related pathways (AGE-1, TOR, Daf-2).
Conclusions:
- PAK1 plays a significant role in regulating C. elegans reproduction and lifespan, supporting the reproduction-lifespan trade-off theory.
- Reduced reproduction and/or HSP16.2 gene activation in C. elegans can serve as early indicators for extended lifespan.
- C. elegans presents a viable model for rapid in vivo screening of potential PAK1-blocking therapeutics for various diseases.
