Suppression of human 8-oxoguanine DNA glycosylase (OGG1) augments ultrasound-induced apoptosis in cervical cancer cells

Pulsed ultrasound prevents lipopolysaccharide-induced muscle atrophy through inhibiting p38 MAPK phosphorylation in C2C12 myotubes

OBJECTIVE

Inflammation contributes to skeletal muscle atrophy via protein degradation induced by p38 mitogen-activated protein kinase (MAPK) phosphorylation. Meanwhile, pulsed ultrasound irradiation provides the mechanical stimulation to the target tissue, and has been reported to show anti-inflammatory effects. This study investigated the preventive effects of pulsed ultrasound irradiation on muscle atrophy induced by lipopolysaccharide (LPS) in C2C12 myotubes.

METHODS

C2C12 myotubes were used in this research. The pulsed ultrasound (a frequency of 3 MHz, duty cycle of 20%, intensity of 0.5 W/cm²) was irradiated to myotube before LPS administration.

RESULTS

The LPS increased phosphorylation of p38 MAPK and decreased the myofibril and myosin heavy chain protein (P < 0.05), followed by atrophy in C2C12 myotubes. The pulsed ultrasound irradiation attenuated p38 MAPK phosphorylation and myotube atrophy induced by LPS (P < 0.05).

CONCLUSIONS

Pulsed ultrasound irradiation has the preventive effects on inflammation-induced muscle atrophy through inhibiting phosphorylation of p38 MAPK.

Base excision repair of oxidative DNA damage: from mechanism to disease

Reactive oxygen species continuously assault the structure of DNA resulting in oxidation and fragmentation of the nucleobases. Both oxidative DNA damage itself and its repair mediate the progression of many prevalent human maladies. The major pathway tasked with removal of oxidative DNA damage, and hence maintaining genomic integrity, is base excision repair (BER). The aphorism that structure often dictates function has proven true, as numerous recent structural biology studies have aided in clarifying the molecular mechanisms used by key BER enzymes during the repair of damaged DNA. This review focuses on the mechanistic details of the individual BER enzymes and the association of these enzymes during the development and progression of human diseases, including cancer and neurological diseases. Expanding on these structural and biochemical studies to further clarify still elusive BER mechanisms, and focusing our efforts toward gaining an improved appreciation of how these enzymes form co-complexes to facilitate DNA repair is a crucial next step toward understanding how BER contributes to human maladies and how it can be manipulated to alter patient outcomes.