ABSTRACT
Intermittent fasting (IF), a dietary pattern alternating between eating and fasting periods within a 24-hour cycle, has garnered recognition for its potential to enhance both healthspan and lifespan in animal models and humans. It also shows promise in alleviating age-related diseases, including neurodegeneration. Vascular cognitive impairment (VCI) spans a severity range from mild cognitive deficits to severe cognitive deficits and loss of function in vascular dementia. Chronic cerebral hypoperfusion has emerged as a significant contributor to VCI, instigating vascular pathologies such as microbleeds, blood-brain barrier dysfunction, neuronal loss, and white matter lesions. Preclinical studies in rodents strongly suggest that IF has the potential to attenuate pathological mechanisms, including excitotoxicity, oxidative stress, inflammation, and cell death pathways in VCI models. Hence, this supports evaluating IF in clinical trials for both existing and at-risk VCI patients. This review compiles existing data supporting IF's potential in treating VCI-related vascular and neuronal pathologies, emphasizing the mechanisms by which IF may mitigate these issues. Hence providing a comprehensive overview of the available data supporting IF's potential in treating VCI by emphasizing the underlying mechanisms that make IF a promising intervention for VCI.
ABSTRACT
Colorectal cancer (CRC) is the second leading cause of cancer deaths. Though chemotherapy is the main treatment option for advanced CRC, patients invariably acquire resistance to chemotherapeutic drugs and fail to respond to the therapy. Although understanding the mechanisms regulating chemoresistance has been a focus of intense research to manage this challenge, the pathways governing resistance to drugs are poorly understood. In this study, we provide evidence for the role of ubiquitin ligase NEDD4 in resistance developed against the most commonly used CRC chemotherapeutic drug 5-fluorouracil (5-FU). A marked reduction in NEDD4 protein abundance was observed in a panel of CRC cell lines and patient-derived xenograft samples that were resistant to 5-FU. Knockout of NEDD4 in CRC cells protected them from 5-FU-mediated apoptosis but not oxaliplatin or irinotecan. Furthermore, NEDD4 depletion in CRC cells reduced proliferation, colony-forming abilities and tumour growth in mice. Follow-up biochemical analysis highlighted the inhibition of the JNK signalling pathway in NEDD4-deficient cells. Treatment with the JNK activator hesperidin in NEDD4 knockout cells sensitised the CRC cells against 5-FU. Overall, we show that NEDD4 regulates cell proliferation, colony formation, tumour growth and 5-FU chemoresistance in CRC cells.