1. Surfactant proteins-A and -D attenuate gut injury and apoptosis
Linlin Zhang1, 2, Qinghe Meng1, Natesh Yepuri1, Guirong Wang1, Xiuming Xi2, Robert N Cooney1
1 Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
2 Intensive Care Unit, Fu Xing Hospital, Capital Medical University, Beijing, , China
 Introduction
 Results
5. SP-A and SP-D regulate SHP-1 activation by LPS.
The surfactant proteins A (SP-A) and D (SP-D) are members of the C-type lectin family which are important in pulmonary immunity and host defense. Surfactant proteins-A and -D KO (SP-A/D KO) mice with pneumonia and sepsis demonstrate more severe lung, kidney and gut injury/apoptosis than WT controls. We hypothesize SP-A and SP-D directly regulate LPS-induced P38 MAPK activation and gut apoptosis during sepsis. This study examines the regulation of LPS-induced inflammation and apoptosis by SP-A/D in primary IECs.
1.SP-A and SP-D regulate LPS-induced apoptosis.
 Materials & Methods
4. SP-A and SP-D regulate TLR4 & CD14 expressions by LPS.
IECs from SP-A/D KO and C57BL/6 WT mice were stimulated with LPS; IECs from C57BL/6 WT mice were stimulated with LPS ± SP-A/D for 20 h of pretreatment. Apoptosis (result 1), P38 MAPK activation (result 2) and TLR4 and CD14 expression (result 4) were assessed at 24 h.
P38 MAPK agonist (U46619) ± SP-A/D and LPS ± inhibitor (SB203580) were used in IECs from C57BL/6 WT mice to assess P38 MAPK role in regulating apoptosis (result 3).
Regulation of SHP-1 activation by LPS & SP-A/D in IECs from C57BL/6 WT mice (result 5).
Apoptosis was assayed by TUNEL, cleaved caspase-3 levels and the ratio of BAX/Bcl-2.
The relative abundance of phosphorylated-P38 MAPK/total-P38 (p-P38 MAPK/t-P38 MAPK, p-SHP-1/t-SHP-1, TLR4 and CD14 were measured by Western Blot.
 Conclusions
2.SP-A and SP-D regulate P38 MAPK activation by LPS.
SP-A and SP-D attenuate the LPS-induced increase in apoptosis, cleaved caspase-3 and BAX/Bcl-2 ratio in primary IECs.
The ability of SP-A and SP-D to attenuate LPS-induced activation of the TLR4 and P38 MAPK signaling pathways represent potential mechanisms for the protective effects of SP-A and SP-D on apoptosis in IECs.   
3 . Regulation of LPS-induced apoptosis by SP-A and SP-D through P38 MAPK phosphorylation.