Control of translation in the cold: implications for therapeutic hypothermia

Frozen? Let it go to reset circadian rhythms

The molecular events in response to severe hyperthermia are not fully understood, and research has focused mainly on the effects of cooling at temperatures between 28°C and 35°C. In a new study, Fischl et al have analysed human cardiomyocytes at lower temperatures (8°C, 18°C and 28°C) and identified a novel mechanism by which hypothermia synchronises the circadian clock: cooling induces nuclear accumulation of transcripts that encode negative regulators of the circadian clock, which are released into the cytoplasm upon rewarming allowing synthesis of specific clock proteins.

RNA binding motif protein 3: a potential biomarker in cancer and therapeutic target in neuroprotection

RNA binding motif 3 (RBM3) is a highly conserved cold-induced RNA binding protein that is transcriptionally up-regulated in response to harsh stresses. Featured as RNA binding protein, RBM3 is involved in mRNA biogenesis as well as stimulating protein synthesis, promoting proliferation and exerting anti-apoptotic functions. Nowadays, accumulating immunohistochemically studies have suggested RBM3 function as a proto-oncogene that is associated with tumor progression and metastasis in various cancers. Moreover, emerging evidences have also indicated that RBM3 is equally effective in neuroprotection. In the present review, we provide an overview of current knowledge concerning the role of RBM3 in various cancers and neuroprotection. Additionally, its potential roles as a promising diagnostic marker for cancer and a possible therapeutic target for neuro-related diseases are discussed.

Traumatic Brain Injury: Current Treatment Strategies and Future Endeavors

Traumatic brain injury (TBI) presents in various forms ranging from mild alterations of consciousness to an unrelenting comatose state and death. In the most severe form of TBI, the entirety of the brain is affected by a diffuse type of injury and swelling. Treatment modalities vary extensively based on the severity of the injury and range from daily cognitive therapy sessions to radical surgery such as bilateral decompressive craniectomies. Guidelines have been set forth regarding the optimal management of TBI, but they must be taken in context of the situation and cannot be used in every individual circumstance. In this review article, we have summarized the current status of treatment for TBI in both clinical practice and basic research. We have put forth a brief overview of the various subtypes of traumatic injuries, optimal medical management, and both the noninvasive and invasive monitoring modalities, in addition to the surgical interventions necessary in particular instances. We have overviewed the main achievements in searching for therapeutic strategies of TBI in basic science. We have also discussed the future direction for developing TBI treatment from an experimental perspective.

Cooling-induced SUMOylation of EXOSC10 down-regulates ribosome biogenesis

The RNA exosome is essential for 3' processing of functional RNA species and degradation of aberrant RNAs in eukaryotic cells. Recent reports have defined the substrates of the exosome catalytic domains and solved the multimeric structure of the exosome complex. However, regulation of exosome activity remains poorly characterized, especially in response to physiological stress. Following the observation that cooling of mammalian cells results in a reduction in 40S:60S ribosomal subunit ratio, we uncover regulation of the nuclear exosome as a result of reduced temperature. Using human cells and an in vivo model system allowing whole-body cooling, we observe reduced EXOSC10 (hRrp6, Pm/Scl-100) expression in the cold. In parallel, both models of cooling increase global SUMOylation, leading to the identification of specific conjugation of SUMO1 to EXOSC10, a process that is increased by cooling. Furthermore, we define the major SUMOylation sites in EXOSC10 by mutagenesis and show that overexpression of SUMO1 alone is sufficient to suppress EXOSC10 abundance. Reducing EXOSC10 expression by RNAi in human cells correlates with the 3' preribosomal RNA processing defects seen in the cold as well as reducing the 40S:60S ratio, a previously uncharacterized consequence of EXOSC10 suppression. Together, this work illustrates that EXOSC10 can be modified by SUMOylation and identifies a physiological stress where this regulation is prevalent both in vitro and in vivo.