Effects Of Umbilical Cord Mesenchymal Stem Cells On Kidney And Lung In Severe Burned Rat

Severe burns can cause systemic multi-organ damage and functional decline,particularly burn patients with multiple organ dysfunction syndromes is the main causeof death. Although mechanism of organ damage after burn is still not fully understood,many studies show that changes of microenvironment in tissues and organs after burnare closely related to their repair and regeneration; especially ischemia, hypoxia andmassive release of inflammatory mediators and oxygen radical production play theimportant roles in multiple organ failure. Numerous studies showed that mesenchymalstem cells (MSCs) can effectively improve local microenvironment to promote cellactivity and repair of damaged tissue.MSCs can be readily isolated from a number of adult and fetal tissues, and havethe capacity of expansion in vitro on a clinical scale. Bone marrow MSCs are able todifferentiate into multiple cell lineages, and preclinical findings from animalexperiments are promising and have shown that human multipotent MSCs may haveconsiderable therapeutic potential in a wide variety of human diseases. However, bonemarrow mesenchymal stem cell was obtained from donor, and proliferation anddifferentiation potential would decrease with donor age increases. Moreover, due to theapplication of BM-of MSCS in the regeneration of damaged tissue repair study can onlybe applied to the treatment of post-treatment, in acute injury, for the early application islimited by the cycle of the cell culture and cannot be applied in time. UCMSCs havesome advantages in wide variety of sources, low immune response, and differentiationpotential advantages. At present, pluripotency of umbilical cord derived-MSCs(UCMSCs) has been confirmed, and has a wide advantage including variety of sources,low immune response, and differentiation potential; therefore UCMSCs can be appliedas a new cell therapy strategies applied to burns, organ damage repair and regeneration.Severe burns can damage multiple organs; damage of kidney tissue is the earlier onset of the complications. The damage of kidney tissue damage is related to a varietyof cytokines, purine pool depletion, increased formation of free radicals and cleardiminished capacity, energy metabolism, apoptosis and necrosis and the effect of otherfactors. Recent studies show that the UCMSCs are involved in the inflammatory tissuecell migration; produce a variety of regeneration factors, and cause tissue andinfiltration of activated macrophages in the mucosa cell inactivation and by promotinghost cell proliferation to repair damaged tissue, UCMSCs may have a good protectiveeffect on early severe burns animals. But it is still unknown for UCMSCs after severetrauma specific organ or tissue in a specific role and mechanism. Acute lung injury (ALI)is caused by a variety of lung internal and external pathogenic factors of acuteprogressive hypoxic respiratory insufficiency; severe trauma is the main reason whypatients die of the extensive burns and serious infections. However, due to thecomplexity of the structure of the lung, the stem cells for the treatment of lung diseasestay backward compared with other organs. In this study, we prepared III degree burnedrat model to observe the effects of UCMSCs on kidney and lung after injury, which setan experimental basis for the stem cells and the mechanism of organ damage.This study has mainly three parts as follows:1. Isolated and cultured UCMSCs and its biological characteristics.In this experiment, using a combination of collagenase digestion and tissue adherent,mesenchymal stem cells were isolated from umbilical cord Wharton (Wharton’s Jelly)Source glue. Expressions of surface antigens, cell proliferative activity and cellspluripotent (fat, bone and cartilage cells) were analysized. Conclusion: UCMSCsexpressed markers of mesenchymal stem cell antigen (CD29, CD44, CD90, CD105),negative expression of hematopoietic cell lines marker CD34. UCMSCs can bedifferentiated into bone alkaline phosphatase positive staining cells, type II collagenantibody staining and positive chondrocytes and Oil Red-O staining positive fat cells.UCMSCs had a strong cell proliferation by MTT assay.2. Kidney protective effects of UCMSCs in severely burned rat.In this experiment, P3-P7UCMSCs were intravenous injected into20%TBSA III degree burn rat model: Ust statin therapy as a positive control group and injected withequivalent volume of saline as a negative control group groups. After healing, UCMSCsin the rat kidney distribution characteristics was observed by frozen section method andimmunohistochemical staining under a fluorescence microscope, the therapeutic effectafter treatment was detected by biochemical tests. Conclusion: After7,14d,histopathology of kidney tissue in rats after stem cell transplantation showed thartreduced redness, swelling and other pathological changes compared with Ulinastatingroup and saline group; immunohistochemist after UCMSCs injury showed thatincreased Bcl-2expression in renal tissue compared with Ulinastatin Ding and salinegroups, indicating that the renal tissue of the anti-apoptotic ability. BUN and Cr weresignificantly decreased in UCMSCs Group. Stem cell therapy seemed to have asignificant effect on improvement of renal function. UCMSCs transplantation caneffectively reduce severe burn rat kidney tissue damage and improve kidney function.3. Protective effects of UCMSCs after early post-traumatic acute lung injuryP3-P7generation UCMSCs intravenous were also taken and20%TBSA III degreeburn rat model (Escherichia coli endotoxin) were used in this experiment. UCMSCsdistribution characteristics in rat lungs were observed by frozen section method andimmunohistochemical staining under a fluorescence microscope. The therapeutic effectwas detected after treatment. Conclusion: Histopathology after7,14d showed thatumbilical cord mesenchymal stem cells can improve the traumatic acute lung injuryanimal blood gas, reduced to varying degrees Serum TNF-α and BALF TNF-α, C3a,C5a and albumin concentration, inhibition of protein expression of lung tissue TNF-α,reduce the extent of tissue damage internal organs. Lung tissue congestion, swelling andother pathological changes after burns in stem cell transplantation was reducedcompared with the Ulinastatin group and the saline group. UCMSCs can reduce thegeneration and content of the tissue and plasma TNF-α and reduce cytokines such asTNF-α mediated multi-organ tissue damage, to some extent, the early post-traumaticacute lung injury protective effect and mitigate the occurrence of MODS development.