In my 40 years experience of medical research, « down regulates” is used only when something slows down a process via a physiologic mechanism (e.g., an increase in the cholesterol content of a cell down-regulates LDL receptor synthesis), not necessarily to normal, whereas « corrects » is generally used to mean « returns to normal from an abnormally high or low state ». This also conforms to the definitions of « corrects » given in dictionaries: eg, 

In Chamber’s Dictionary: « To bring to a normal state »

In Merriam-Webster Dictionary: « To make or set right »

So there is a big difference (if they are using them correctly!)