Organ-Specific Differentiation of Human Adipose-Derived Stem Cells in Various Organs of Xenotransplanted Rats: A Pilot Study.

Adipose-derived stem cells (ADSCs) are potential therapeutics considering their self-renewal capacity and ability to differentiate into all somatic cell types in vitro. The ideal ADSC-based therapy is a direct injection into the relevant organs. The objective of this study was to investigate the viability and safety of intra-organ human ADSC (h-ADSC) xenotransplants in vivo. Subcutaneous adipose tissue from the abdominal area of 10 patients was sampled. h-ADSCs were isolated from adipose tissue samples and identified using immunofluorescence antibodies. Multi-differentiation potential assays for adipocytes, osteocytes, and chondrocytes were performed. Cultured h-ADSCs at passage 4 were transplanted into multiple organs of 17 rats, including the skin, subcutaneous layer, liver, kidney, pancreas, and spleen. The h-ADSC-injected organs excised after 100 days were examined, and the survival of h-ADSCs was measured by quantitative real-time polymerase chain reaction (qRT-PCR) using specific human and rat target genes. h-ADSCs confirmed by stem cell phenotyping were induced to differentiate into adipogenic, osteogenic, and chondrogenic lineages in vitro. All rats were healthy and exhibited no side effects during the study; the transplanted h-ADSCs did not cause inflammation and were indiscernible from the native organ cells. The presence of transplanted h-ADSCs was confirmed using qRT-PCR. However, the engrafted survival rates varied as follows: subcutaneous fat (70.6%), followed by the liver (52.9%), pancreas (50.0%), kidney (29.4%), skin (29.4%), and spleen (12.5%). h-ADSCs were successfully transplanted into a rat model, with different survival rates depending on the organ.

Preliminary report of preclinical trial of multi-genome engineering pig-to-macaque heart, liver and kidney transplantation / 器官移植

Objective To investigate the application prospect of the most extensive genome engineering pig internationally in preclinical xenotransplantation. Methods Porcine endogenous retrovirus (PERV) knockout combined with 3 major heterologous antigen gene knockouts and 9 humanized genes for inhibition of complement activation, regulation of coagulation disorders, anti-inflammatory and anti-phagocytosis were transferred into a pig (PERV-KO/3-KO/9-TG) as a donor, and the heart, liver and kidney were obtained and transplanted to 3 Rhesus macaque recipients respectively to establish a preclinical research model of pig-to-Rhesus macaque xenotransplantation. The functional status of xenografts after blood flow reconstruction was observed and the survival of recipients was summarized. The hemodynamics of xenografts were monitored. The change of hematological indexes of each recipient was compared. The histopathological manifestation of xenografts was observed. Results After the blood flow was reconstructed, all xenografts showed ruddy color, soft texture and good perfusion. The transplant heart, liver and kidney showed full arterial and venous blood flow and good perfusion at 1 d after operation. The postoperative survival time of heart, liver, and kidney transplant recipients was 7, 26, and 1 d, respectively. The levels of creatine kinase, creatine kinase isoenzyme, and lactate dehydrogenase increased in heart transplant recipient at 1 d after operation, and gradually recovered to near normal levels at 6 d after operation. All indexes increased sharply at 7 d after operation. The level of aspartate aminotransferase increased in liver transplant recipients at 2 d after operation, and the alanine aminotransferase basically returned to normal at 10 d after operation, but the total bilirubin continued to increase. Both aspartate aminotransferase and alanine aminotransferase increased at 12 d after operation, and reached a peak at 15 d after operation. The kidney transplant recipient developed mild proteinuria at 1 d after operation, and died of sudden severe arrhythmia. Histopathology showed that the tissue structure of cardiac and renal xenografts was close to normal, and liver xenografts presented with patchy necrosis, the liver tissue structure was disordered, accompanied by inflammatory damage, interstitial hemorrhage and thrombotic microangiopathy. Conclusions PERV-KO/3-KO/9-TG pig shows advantages in overcoming hyperacute rejection, mitigating humoral rejection and coagulation dysregulation. However, whether it can be used as potential donor for clinical xenotransplantation needs further evaluation.

Student nurses at Spanish universities and their attitude toward xenotransplantation.

INTRODUCTION: Recent immunological and transgenic advances are a promising alternative using limited materials of human origin for transplantation. However, it is essential to achieve social acceptance of this therapy. OBJECTIVE: To analyze the attitude of nursing students from Spanish universities toward organ xenotransplantation (XTx) and to determine the factors affecting their attitude. MATERIALS AND METHODS: Type of study: A sociological, multicentre, and observational study. STUDY POPULATION: Nursing students enrolled in Spain (n = 28,000). SAMPLE SIZE: A sample of 10 566 students estimating a proportion of 76% (99% confidence and precision of ±1%), stratified by geographical area and year of study. Instrument of measurement: A validated questionnaire (PCID-XenoTx-RIOS) was handed out to every student in a compulsory session. This survey was self-administered and self-completed voluntarily and anonymously by each student in a period of 5-10 min. STATISTICAL ANALYSIS: descriptive analysis, Student's t test, the chi-square test, and a logistic regression analysis. RESULTS: A completion rate: 84% (n = 8913) was obtained. If the results of XTx were as good as in human donation, 74% (n = 6564) would be in favor and 22% (n = 1946) would have doubts. The following variables affected this attitude: age (P < 0.001); sex (P < 0.001); geographical location (P < 0.001); academic year of study (P < 0.001); attitude toward organ donation (P < 0.001); belief in the possibility of needing a transplant (P < 0.001); discussion of transplantation with one's family (P < 0.001) and friends (P < 0.001); and the opinion of one's partner (P < 0.001). The following variables persisted in the multivariate analysis: being a male (OR = 1.436; P < 0.001); geographical location (OR = 1.937; P < 0.001); an attitude in favor of donation (OR = 1.519; P < 0.001); belief in the possibility of needing a transplant (OR = 1.497; P = 0.036); and having spoken about the issue with family (OR = 1.351; P < 0.001) or friends (OR = 1.240; P = 0.001). CONCLUSIONS: The attitude of nursing students toward organ XTx is favorable and is associated with factors of general knowledge about organ donation and transplantation and social interaction.

Xenotransplantation.

The transplantation of living cells, tissues or organs from one species to another is termed xenotransplantation. The history of xenotransplantation is as old as allogeneic transplantation itself. Early attempts were made at a time when the immunologic basis of organ rejection were poorly understood. The advent of potent immunosuppressive medications along with the parallel advances in the field of genetic engineering has provided a fresh perspective on the role of xenotransplantation as a means to alleviate the disparity between the number of candidates on the waitlist and the available organs. As the science behind xenotransplantation advances, the transplantation community must take it upon themselves to educate the community at large regarding both the benefits and potential risks of this promising field.