mice

Viewing posts tagged mice

27 Feb 2020

Transgenic animal models demonstrate that mice have similar COPD-related skeletal muscle dysfunction as humans

By nickwiecien

Balnis et al (2020) recently studied the mechanisms of COPD-related skeletal muscle dysfunction using an established transgenic animal model of COPD in a recently published paper in the Journal of Applied Physiology. 

Patients with chronic obstructive pulmonary disease (COPD), a disease that is characterized by obstructed airflow to the lungs and is associated with long-term exposure to cigarette smoke, often also develop skeletal muscle dysfunction. Overall, the comorbidity of COPD and skeletal muscle dysfunction is associated with outcomes such as poor health and mortality.

While some research has suggested that skeletal muscle dysfunction may be the result of COPD-related conditions, such as protein degradation and metabolic disruption, there is still poor understanding on what mechanisms would regulate these processes, as there is little to no research on a validated animal model of pulmonary emphysema. Therefore, Balnis et al (2020) sought to use such a model based on inducible UL-13-driven pulmonary emphysema (IL-13TG) to study the mechanisms of skeletal muscle dysfunction.

Using a transgenic mouse model, researchers found that the skeletal muscles of emphysematous mice are similar to those developed by human patients with COPD. For instance, both groups develop muscular atrophy and have decreased oxygen consumption. Within skeletal muscles, both groups also had downregulated ATP binding and bioenergetics.

Researchers concluded that transgenic animal models of COPD are useful to understand skeletal-muscle dysfunction in humans.

11 Sep 2019

NCQBCS Scientists Publish on Essential Phosphatase Pptc7

By nickwiecien

Niemi et al analyzed a Pptc7 matrix phosphatase in mice in a recent issue of Nature Communications.

This paper addressed the functionality of phosphorylation in mitochondrial proteins. While mitochondrial proteins tend to have a lot of phosphorylation, it is also possible that protein dephosphorylation (the opposite process) may be significant in controlling various mitochondrial processes.

To test this, researchers deleted the matrix phosphatase Pptc7 from mice using the CRISPR-Cas9. As a result, mice were born with normal transcript levels but less mitochondria and protein in their tissues. They also had more phosphorylation in certain mitochondrial proteins. These mice developed hypoketonic hypoglycemia, had higher levels of acylcarnitines and serum lactate, and died shortly after being born. 

Analyzing this data, researchers pinpointed that the protein translocase complex subunit Timm50 is probably a Pptc7 substrate whose phosphorylation lowers import activity.  This data also demonstrates that Pptc7 is necessary for healthy mammalian mitochondrial processes, such as metabolism, and biogenesis after birth.