In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: In human renal mesangial cells , high glucose induced ROS production and activated expression of Nrf2 and its downstream genes .
### Output Text:
In human renal mesangial cells , high <span class="chemical">glucose</span> induced ROS production and activated expression of Nrf2 and its downstream genes . 