Mammalian cold-inducible RNA-binding protein facilitates wound healing through activation of AMP-activated protein kinase

The potential of cold-shock promoters for the expression of recombinant proteins in microbes and mammalian cells

BACKGROUND

Low-temperature expression of recombinant proteins may be advantageous to support their proper folding and preserve bioactivity. The generation of expression vectors regulated under cold conditions can improve the expression of some target proteins that are difficult to express in different expression systems. The cspA encodes the major cold-shock protein from Escherichia coli (CspA). The promoter of cspA has been widely used to develop cold shock-inducible expression platforms in E. coli. Moreover, it is often necessary to employ expression systems other than bacteria, particularly when recombinant proteins require complex post-translational modifications. Currently, there are no commercial platforms available for expressing target genes by cold shock in eukaryotic cells. Consequently, genetic elements that respond to cold shock offer the possibility of developing novel cold-inducible expression platforms, particularly suitable for yeasts, and mammalian cells.

CONCLUSIONS

This review covers the importance of the cellular response to low temperatures and the prospective use of cold-sensitive promoters to direct the expression of recombinant proteins. This concept may contribute to renewing interest in applying white technologies to produce recombinant proteins that are difficult to express.

Innate Immunity as an Executor of the Programmed Death of Individual Organisms for the Benefit of the Entire Population

In humans, over-activation of innate immunity in response to viral or bacterial infections often causes severe illness and death. Furthermore, similar mechanisms related to innate immunity can cause pathogenesis and death in sepsis, massive trauma (including surgery and burns), ischemia/reperfusion, some toxic lesions, and viral infections including COVID-19. Based on the reviewed observations, we suggest that such severe outcomes may be manifestations of a controlled suicidal strategy protecting the entire population from the spread of pathogens and from dangerous pathologies rather than an aberrant hyperstimulation of defense responses. We argue that innate immunity may be involved in the implementation of an altruistic programmed death of an organism aimed at increasing the well-being of the whole community. We discuss possible ways to suppress this atavistic program by interfering with innate immunity and suggest that combating this program should be a major goal of future medicine.

Cold-Induced RNA-Binding Protein Promotes Glucose Metabolism and Reduces Apoptosis by Increasing AKT Phosphorylation in Mouse Skeletal Muscle Under Acute Cold Exposure

The main danger of cold stress to animals in cold regions is systemic metabolic changes and protein synthesis inhibition. Cold-induced RNA-binding protein is a cold shock protein that is rapidly up-regulated under cold stimulation in contrast to the inhibition of most proteins and participates in multiple cellular physiological activities by regulating targets. Therefore, this study was carried out to investigate the possible mechanism of CIRP-mediated glucose metabolism regulation and survival promotion in skeletal muscle after acute cold exposure. Skeletal muscle and serum from mice were obtained after 0, 2, 4 and 8 h of acute hypothermia exposure. Subsequently, the changes of CIRP, metabolism and apoptosis were examined. Acute cold exposure increased energy consumption, enhanced glycolysis, increased apoptosis, and up-regulated CIRP and phosphorylation of AKT. In addition, CIRP overexpression in C2C12 mouse myoblasts at each time point under 37°C and 32°C mild hypothermia increased AKT phosphorylation, enhanced glucose metabolism, and reduced apoptosis. CIRP knockdown by siRNA interference significantly reduced the AKT phosphorylation of C2C12 cells. Wortmannin inhibited the AKT phosphorylation of skeletal muscle after acute cold exposure, thereby inhibiting glucose metabolism and aggravating apoptosis. Taken together, acute cold exposure up-regulates CIRP in mouse skeletal muscle, which regulates glucose metabolism and maintains energy balance in skeletal muscle cells through the AKT signaling pathway, thus slowing down the apoptosis of skeletal muscle cells.