Human Endothelial Cell Seeding in Partially Decellularized Kidneys.

The excessive demand for organ transplants has promoted the development of strategies that increase the supply of immune compatible organs, such as xenotransplantation of genetically modified pig organs and the generation of bioartificial organs. We describe a method for the partial replacement of rat endothelial cells for human endothelial cells in a rat's kidney, obtaining as a final result a rat-human bioartificial kidney. First, in order to maintain parenchymal epithelial cells and selectively eliminate rat endothelial cells, three methods were evaluated in which different solutions were perfused through the renal artery: 0.1% sodium dodecyl sulfate (SDS), 0.01% SDS, and hyperosmolar solutions of sucrose. Then, partially decellularized kidneys were recellularized with human endothelial cells and finally transplanted in an anesthetized rat. The solution of 0.1% SDS achieved the highest vascular decellularization but with high degree of damage in the parenchyma side. On the contrary, 0.01% SDS and hyperosmolar solutions achieved a partial degree of endothelial decellularization. TUNEL assays reveal that hyperosmolar solutions maintained a better epithelial cell viability contrasting with 0.01% SDS. Partially decellularized kidneys were then recellularized with human endothelial cells. Histological analysis showed endothelial cells attached in almost all the vascular bed. Recellularized kidney was transplanted in an anesthetized rat. After surgery, recellularized kidney achieved complete perfusion, and urine was produced for at least 90 min posttransplant. Histological analysis showed endothelial cells attached in almost all the vascular bed. Therefore, endothelial decellularization of grafts and recellularization with human endothelial cells derived from transplant recipients can be a feasible method with the aim to reduce the damage of the grafts.

Secretory Leukocyte Proteinase Inhibitor Protects Acute Kidney Injury Through Immune and Non-Immune Pathways.

ABSTRACT: Acute kidney injury (AKI) is characterized by rapid loss of excretory function and is the clinical manifestation of several disorders affecting the kidney. The aim of the present study was to investigate the mechanism of action of Secretory Leukocyte Proteinase Inhibitor (SLPI) that protects the kidneys form AKI. In vivo and in vitro experiments were performed to assess the effect of SLPI on kidney injury. Animal models of kidney injury was generated by 40 min obstruction of kidney artery and vein (ischemia-reperfusion injury model) or daily administration of 60 mg/kg/day of gentamicine for 5 day (gentamicin-associated AKI model). For in vitro assessment, human renal epithelium HK-2 cells were cultured under serum starvation conditions or with tacrolimus. The administration of SLPI (250 µg/kg, i.p.) reduced elevated plasma creatinine and blood urea nitrogen levels, tissue myeloperoxidase content, and acute tubular necrosis induced by kidney damage. Furthermore, SLPI treatment reduced CD86, CD68, CD14, CCL2, TNFα, and IL-10 transcripts in kidney biopsies. To further analyze a direct effect of SLPI on renal epithelial cells, HK-2 cells from human renal epithelium were cultured under serum starvation conditions or with tacrolimus. Both conditions induced apoptosis of HK-2 cells which was reduced when SLPI was present in the culture medium. Furthermore, SLPI favored the proliferation and migration of HK-2 cells. An analysis of the gene profiles of HK-2 cells treated with calcineurin inhibitors affected inflammatory and non-inflammatory pathways that were reversed by SLPI. Among them, SLPI down modulated the expression of CCL2, SLC5A3, and BECN1 but up-regulated the expression of TLR4, ATF4, ATF6, HSP90B, BBC3 SLC2A1, and TNFRSF10B. Overall, these results suggest that SLPI, in addition to its activity on immune cells, may directly target tubular epithelial cells of the kidney to mediate the nephroprotective activity in AKI.

SLPI in the perfusion solution helps to identify graft quality in kidney transplants.

Aim: It is important to find biomarkers that identify the graft quality in kidney transplantation. Results & methodology: The level of SLPI in the cold preservation solution was used as a marker to predict early kidney graft function after transplantation. Before transplantation, kidneys were washed and SLPI was measured in the discarded solution. A retrospective analysis showed that patients with delayed graft function or rejection episodes in post-trasplant, had higher SLPI concentrations in the perfusion solution than patients without delayed graft function or rejections. Furthermore, SLPI could discriminate between patients with better or worse estimated glomerular filtration rate among low-risk patients (kidney donor profile index <80). Discussion & conclusion: These results suggest that the SLPI concentration in the perfusion solutions could be a predictor of short-term organ function and a complement to the kidney donor profile index score.

α-lipoic acid reduces postreperfusion syndrome in human liver transplantation - a pilot study.

A double-blind randomized controlled trial was performed to compare the safety and efficacy of α-lipoic acid (ALA) in liver transplantation (LT). The grafts were randomized to receive ALA or placebo before the cold ischemia time. Furthermore, patients transplanted with the ALA-perfused graft received 600 mg of intravenous ALA, while patients with the nonperfused graft received the placebo just before graft reperfusion. Hepatic biopsy was performed 2 h postreperfusion. Blood samples were collected before, during and 1 and 2 days after reperfusion. Quantitative polymerase chain reaction (qPCR) analysis was performed on biopsies to assess genes involved in the response to hypoxia, apoptosis, cell growth, survival and proliferation, cytokine production and tissue damage protection. Nine of 40 patients developed postreperfusion syndrome (PRS), but seven of them belonged to the control group. There was a decrease in PHD2 and an increase in alpha subunit of hypoxia-inducible factor-1 (HIF-1α) and baculoviral IAP repeat containing 2 (Birc2) transcript levels in the biopsies from the ALA-treated versus the control group of patients. Additionally, plasma levels of alarmins were lower in ALA-treated patients than control patients, which suggests that ALA-treated grafts are less inflammatory than untreated grafts. These results showed that ALA is safe for use in LT, induces gene changes that protect against hypoxia and oxidative stress and reduces the appearance of PRS.

Alpha Lipoic Acid: A Therapeutic Strategy that Tend to Limit the Action of Free Radicals in Transplantation.

Organ replacement is an option to mitigate irreversible organ damage. This procedure has achieved a considerable degree of acceptance. However, several factors significantly limit its effectiveness. Among them, the initial inflammatory graft reaction due to ischemia-reperfusion injury (IRI) has a fundamental influence on the short and long term organ function. The reactive oxygen species (ROS) produced during the IRI actively participates in these adverse events. Therapeutic strategies that tend to limit the action of free radicals could result in beneficial effects in transplantation outcome. Accordingly, the anti-oxidant α-lipoic acid (ALA) have been proved to be protective in several animal experimental models and humans. In a clinical trial, ALA was found to decrease hepatic IRI after hepatic occlusion and resection. Furthermore, the treatment of cadaveric donor and recipient with ALA had a protective effect in the short-term outcome in simultaneous kidney and pancreas transplanted patients. These studies support ALA as a drug to mitigate the damage caused by IRI and reinforce the knowledge about the deleterious consequences of ROS on graft injury in transplantation. The goal of this review is to overview the current knowledge about ROS in transplantation and the use of ALA to mitigate it.

α-Lipoic Acid Protects Against Ischemia-Reperfusion Injury in Simultaneous Kidney-Pancreas Transplantation.

BACKGROUND: Multiple factors have been implicated in the process of ischemia-reperfusion injury (IRI) in organ transplantation. Among these factors, oxidative damage seems to initiate the injury. α-lipoic acid (ALA) is a potent antioxidant that is used in patients with diabetic polyneuropathy. The aim of the present study was to determine the effect of ALA in patients undergoing simultaneous kidney-pancreas transplant by evaluating the functional recovery of the graft and biochemical markers of IRI. METHODS: Twenty-six patients were included in the following groups: (i) untreated control; (ii) donor and recipient (DR) ALA-treated, in which ALA was administered both to the deceased donor and to the recipients; and (iii) recipient ALA-treated group. The expression of inflammatory genes, as observed in biopsies taken at the end of surgery, as well as the serum cytokines, secretory leukocyte protease inhibitor, regenerating islet-derived protein 3ß/pancreatitis-associated protein, amylase, lipase, glucose, and creatinine levels were quantified as markers of organ function. RESULTS: The DR group showed high levels of TGFß and low levels of C3 and TNFα in the kidneys, whereas high levels of C3 and heme oxygenase were identified in pancreas biopsies. Decreases in serum IL-8, IL-6, secretory leukocyte protease inhibitor, and regenerating islet-derived protein 3 ß/pancreatitis-associated protein were observed after surgery in the DR group. Serum lipase and amylase were lower in the DR group than in the control and recipient groups. Early kidney dysfunction and clinical pancreatitis were higher in the control group than in either treatment group. CONCLUSIONS: These results show that ALA preconditioning is capable of reducing inflammatory markers while decreasing early kidney dysfunction and clinical posttransplant pancreatitis.

Gene expression profile in delay graft function: inflammatory markers are associated with recipient and donor risk factors.

BACKGROUND: Delayed graft function (DGF) remains an important problem after kidney transplantation and reduced long-term graft survival of the transplanted organ. The aim of the present study was to determine if the development of DGF was associated with a specific pattern of inflammatory gene expression in expanded criteria of deceased donor kidney transplantation. Also, we explored the presence of correlations between DGF risk factors and the profile that was found. METHODS: Seven days after kidney transplant, a cDNA microarray was performed on biopsies of graft from patients with and without DGF. Data was confirmed by real-time PCR. Correlations were performed between inflammatory gene expression and clinical risk factors. RESULTS: From a total of 84 genes analyzed, 58 genes were upregulated while only 1 gene was downregulated in patients with DGF compared with no DGF (P = 0.01). The most relevant genes fold changes observed was IFNA1, IL-10, IL-1F7, IL-1R1, HMOX-1, and TGF-ß. The results were confirmed for IFNA1, IL-1R1, HMOX-1 and TGF-ß. A correlation was observed between TGF-ß, donor age, and preablation creatinine, but not body mass index (BMI). Also, TGF-ß showed an association with recipient age, while IFNA1 correlated with recipient BMI. Furthermore, TGF-ß, IFNA1 and HMOX-1 correlated with several posttransplant kidney function markers, such as diuresis, ultrasound Doppler, and glycemia. CONCLUSIONS: Overall, the present study shows that DGF is associated with inflammatory markers, which are correlated with donor and recipient DGF risk factors.