ObjectiveTo review the characteristics of human defensin 5 (HD-5), including molecular structure, antibacterial activity and gene expression, and to show its development prospect as a new drug in the treatment of enterogenic infection. MethodsThe published papers about HD-5 were reviewed to summarize its research progress. ResultsBeing a 3-5 KDa cationic peptide rich in cysteine and arginine, especially without glycosylated side-chain, HD-5 plays its antibacterial role against positive and negative Gram’s bacterium, fungi, spirochete, protozoan and enveloped virus with the special active center composed of three disulfide bonds. HD-5 encoding gene alpha defensin 5 (DEFA5) localizes at the 8th chromosome P21-pter with 449 bp, which includes five pieces of sequence: 5′ untranslated region (1-40)，signal peptide (41-97), propiece (98-226), mature peptide (227-322)，and Poly A (433-438).ConclusionAs a broad-spectrum and effective endogenous antimicrobial peptide, HD-5 would be a promising alternative peptide against enterogenic infection if the accessibility to its mass production is settled.
Objective To summarize and review the heterogeneity of bone marrow derived stem cells (BMDSCs) and its formation mechanism and significance, and to analyze the possible roles and mechanisms in intestinal epithel ial reconstruction. Methods The related l iterature about BMDSCs heterogeneity and its role in intestinal epithel ial repair was reviewed and analyzed. Results The heterogeneity of BMDSCs provided better explanations for its multi-potency. The probable mechanisms of BMDSCs to repair intestinal epithel ium included direct implantation into intestinal epithel ium, fusion between BMDSCs and intestinal stem cells, and promotion of injury microcirculation reconstruction. Conclusion BMDSCs have a bright future in gastrointestinal injury caused by inflammatory bowl disease and regeneration.