Targeting PGC1α to wrestle cancer: a compelling therapeutic opportunity

Photobiomodulation modulates mitochondrial energy metabolism and ameliorates neurological damage in an APP/PS1 mousmodel of Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disease. Amyloid β-protein (Aβ) is one of the key pathological features of AD, which is cytotoxic and can damage neurons, thereby causing cognitive dysfunction. Photobiomodulation (PBM) is a non-invasive physical therapy that induces changes in the intrinsic mechanisms of cells and tissues through low-power light exposure. Although PBM has been employed in the treatment of AD, the effect and precise mechanism of PBM on AD-induced neurological damage are still unclear.

METHODS

In vivo experiments, PBM (808 nm, 20 mW/cm2) was used to continuously interfere with APP/PS1 mice for 6 weeks, and then their cognitive function and AD pathological changes were evaluated. In vitro experiments, lipopolysaccharide (LPS) was used to induce microglia to model inflammation, and the effect of PBM treatment on microglia polarization status and phagocytic Aβ ability was evaluated. Hexokinase 2 (HK2) inhibitor 3-bromopyruvate (3BP) was used to study the effect of PBM treatment on mitochondrial energy metabolism in microglia.

RESULTS

PBM further ameliorates AD-induced cognitive impairment by alleviating neuroinflammation and neuronal apoptosis, thereby attenuating nerve damage. In addition, PBM can also reduce neuroinflammation by promoting microglial anti-inflammatory phenotypic polarization; Promotes Aβ clearance by enhancing the ability of microglia to engulf Aβ. Among them, PBM regulates microglial polarization and inhibits neuronal apoptosis, which may be related to its regulation of mitochondrial energy metabolism, promotion of oxidative phosphorylation, and inhibition of glycolysis.

CONCLUSION

PBM regulates neuroinflammatory response and inhibits neuronal apoptosis, thereby repairing Aβ-induced neuronal damage and cognitive dysfunction. Mitochondrial energy metabolism plays an important role in PBM in improving nerve injury in AD mice. This study provides theoretical support for the subsequent application of PBM in the treatment of AD.

Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1) family in physiological and pathophysiological process and diseases

Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1) family (PGC-1s), consisting of three members encompassing PGC-1α, PGC-1β, and PGC-1-related coactivator (PRC), was discovered more than a quarter-century ago. PGC-1s are essential coordinators of many vital cellular events, including mitochondrial functions, oxidative stress, endoplasmic reticulum homeostasis, and inflammation. Accumulating evidence has shown that PGC-1s are implicated in many diseases, such as cancers, cardiac diseases and cardiovascular diseases, neurological disorders, kidney diseases, motor system diseases, and metabolic disorders. Examining the upstream modulators and co-activated partners of PGC-1s and identifying critical biological events modulated by downstream effectors of PGC-1s contribute to the presentation of the elaborate network of PGC-1s. Furthermore, discussing the correlation between PGC-1s and diseases as well as summarizing the therapy targeting PGC-1s helps make individualized and precise intervention methods. In this review, we summarize basic knowledge regarding the PGC-1s family as well as the molecular regulatory network, discuss the physio-pathological roles of PGC-1s in human diseases, review the application of PGC-1s, including the diagnostic and prognostic value of PGC-1s and several therapies in pre-clinical studies, and suggest several directions for future investigations. This review presents the immense potential of targeting PGC-1s in the treatment of diseases and hopefully facilitates the promotion of PGC-1s as new therapeutic targets.

Mitochondria Deregulations in Cancer Offer Several Potential Targets of Therapeutic Interventions

Mitochondria play a key role in cancer and their involvement is not limited to the production of ATP only. Mitochondria also produce reactive oxygen species and building blocks to sustain rapid cell proliferation; thus, the deregulation of mitochondrial function is associated with cancer disease development and progression. In cancer cells, a metabolic reprogramming takes place through a different modulation of the mitochondrial metabolic pathways, including oxidative phosphorylation, fatty acid oxidation, the Krebs cycle, glutamine and heme metabolism. Alterations of mitochondrial homeostasis, in particular, of mitochondrial biogenesis, mitophagy, dynamics, redox balance, and protein homeostasis, were also observed in cancer cells. The use of drugs acting on mitochondrial destabilization may represent a promising therapeutic approach in tumors in which mitochondrial respiration is the predominant energy source. In this review, we summarize the main mitochondrial features and metabolic pathways altered in cancer cells, moreover, we present the best known drugs that, by acting on mitochondrial homeostasis and metabolic pathways, may induce mitochondrial alterations and cancer cell death. In addition, new strategies that induce mitochondrial damage, such as photodynamic, photothermal and chemodynamic therapies, and the development of nanoformulations that specifically target drugs in mitochondria are also described. Thus, mitochondria-targeted drugs may open new frontiers to a tailored and personalized cancer therapy.