Lung protective effects of IT administration of PKCδ-TAT in the setting of sepsis-induced indirect lung injury are specific to the PKCδ inhibitory peptide sequence. H&E staining in representative lung tissue sections from 24 hours after surgery (n = 4 animals per group). A: In the sham-surgery group, lung architecture was normal, with open alveoli and thin alveolar walls. B: In the CLP+PBS group, by 24 hours sepsis had induced indirect pulmonary injury, with widespread inflammatory infiltrate, thickening of alveolar walls and septa, as well as visible hemorrhaging and proteinaceous exudate filling some alveoli. C: In the CLP+TAT-TAT group, histopathological features were similar to those of the CLP+PBS group, indicating that the TAT peptide sequence does not exert a lung-protective effect. D: PKCδ inhibition limited the development of histological changes consistent with lung injury, with reduced inflammatory infiltrate, maintenance of alveolar wall thickness, and an absence of hemorrhaging and proteinaceous exudate induced by sepsis. Scale bars: 100 μm (left column); 50 μm (right column). Original magnification: ×100 (left column); ×400 (right column).