Evaluation of CIRBP and ONECUT2 for fatal hypothermia identification - a pilot study

Due to the lack of specificity in diagnosing death from hypothermia through anatomical and pathological examinations, it is often necessary to rule out other causes of death, such as injury or disease. Thus, finding a method that can distinguish fatal hypothermia from deaths due to alternative causes poses a significant challenge in forensic practice. Cold-inducible RNA-binding protein (CIRBP), a cold shock protein, increases when the body temperature drops below 32 °C. Recently, an increasing number of researchers have focused on the role of CIRBP in response to cold stress. However, few studies have evaluated the value of CIRBP in the forensic identification of fatal hypothermia. To address this, we established a rat model of fatal hypothermia and examined the expression of CIRBP in the brain, which is considered a key organ for thermoregulation. Additionally, we employed catRAPID omics v2.1 and RNA sequencing to predict the potential targets of CIRBP. Finally, we modeled scenarios commonly observed in cases of death from hypothermia-diabetes, alcoholism, and starvation-to assess the limitations of CIRBP and its potential target ONECUT2 in the identification of fatal hypothermia. The results indicated that CIRBP and ONECUT2 in the prefrontal cortex (PFc) may be potential biomarkers for identifying fatal hypothermia. Moreover, ONECUT2 was found to be less influenced by individual conditions such as diabetes and alcoholism compared to CIRBP.