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: Increased expression and apical targeting of renal ENaC subunits in puromycin aminonucleoside - induced nephrotic syndrome in rats .
### Output Text:
Increased expression and apical targeting of renal ENaC subunits in <span class="chemical">puromycin aminonucleoside</span> - induced nephrotic syndrome in rats . 