Vol. 24, Issue 2: Spring 2017

Bioengineered hemoglobin-like protein paves way for potential clinical cure to CO poisoning

Patrick Lin

Many of us probably have experienced this scenario before: while pan-frying some leafy vegetables, a few seconds of inattention lead to sharp alarm beeps following billowing clouds of grey smoke erupting from the now-burnt food. You proceed to take the smoke detector off from the wall to turn it off. What you don’t know is that the detector also detects carbon monoxide, a colorless, odorless, and gaseous compound that many call the “silent killer.” Currently, no “cure” for acute carbon monoxide poisoning exists. But the best way to stop effects of poisoning, such as headache, vomiting, confusion, etc is to immediately stop exposure to CO gas and if needed, by using hyperbaric oxygen to “force” oxygen replenishment in the body.

From 1999 to 2010, “a total of 5,149 deaths from unintentional carbon monoxide poisoning occurred in the United States, an average of 430 deaths per year,” according to a CDC report that utilized public mortality files. Unfortunately, many of these deaths could have been prevented. By understanding the risks of gas-burning appliances including furnaces, generators, cars that may be emitting large amounts of CO due to poor maintenance, or by making sure your home has proper ventilation, it would be difficult for CO to accumulate to dangerous levels.

Physiologically, CO binds to oxygen-carrying molecules called hemoglobin, reducing the amount of oxygen trafficked to tissues. This leads to oxygen starvation of the body, and depending on severity of oxygen deprivation, symptoms can range from dizziness and headache to poisoning in the central nervous system and even death, if the patient is not treated. Recently, researchers made bioengineering changes to neuroglobin, a hemoglobin-like molecule that acts as a trap for CO so that hemoglobin can continue binding to oxygen. After injecting mice with this modified molecule and exposing the mice to lethal levels of CO, the mice showed improvements in physiological function and survived. Those mice exposed to the same levels of CO did not. In other experiments with non-lethal exposures of CO, it is shown that CO doesn’t attach to hemoglobin as well as the control groups. This implies that this modified compound can act as a sort of neutralizer that protects the critical hemoglobin by taking the brunt of CO intake into the body. Subsequently, the compound could be excreted from the mice with no significant adverse side effects.

Many questions remain to be answered, such as those related to safety, shelf life, cost, and possible effects to other organs. But this compound may be soon used in situations of acute poisoning to treat patients after removal from CO sources. Because of its speed, researchers are starting to call it the first possible antidote to a century old health issue. If clinical trials can be approved and the proper precautions made, this compound can even be produced as some sort of over-the-counter medicine. Time will tell, and we will wait.