Urinary transglutaminase 2 as a potent biomarker to predict interstitial fibrosis and tubular atrophy of kidney allograft during early posttransplant period in deceased donor kidney transplantation

PURPOSE: Transglutaminase type 2 (TG2) is an extracellular matrix crosslinking enzyme with a pivotal role in kidney fibrosis. We tested whether quantification of urinary TG2 may represent a noninvasive method to estimate the severity of kidney allograft fibrosis. METHODS: We prospectively collected urine specimens from 18 deceased donor kidney transplant recipients at 1-day, 7-day, 1-month, 3-month, and 6-month posttransplant. In addition, kidney allograft tissue specimens at 0-day and 6-month posttransplant were sampled to analyze the correlation of urinary TG2 and kidney allograft fibrosis. RESULTS: Thirteen recipients had increased interstitial fibrosis and tubular atrophy (IFTA) scores at the 6-month protocol biopsy (IFTA group). The mean level of urinary TG2 in the IFTA group was higher compared to that of 5 other recipients without IFTA (no IFTA group). Conversely, the mean level of urinary syndecan-4 in the IFTA group was lower than levels in patients without IFTA. In the IFTA group, double immunofluorescent staining revealed that TG2 intensity was significantly upregulated and colocalizations of TG2/heparin sulfate proteoglycan and nuclear syndecan-4 were prominent, usually around tubular structures. CONCLUSION: Urinary TG2 in early posttransplant periods is a potent biomarker for kidney allograft inflammation or fibrosis.

Experimental Micro Encapsulation of Pancreatic Islets with Air-driven Droplet Generator and Alginate / 대한이식학회지

PURPOSE: Transplantation of microencapsulated islets is proposed as an ideal therapy for the treatment of type 1 diabetes mellitus without immunosuppression. This is based on the principle that foreign cells are protected from the host immune system by an artificial membrane. The aim of this study is to establish an ideal condition of microencapsulation by using an air-driven droplet generator and alginate in vitro. METHODS: Islets were prepared from Sprague Dawley rat and semi SPF-micro pig. Alginate concentrations were changed from 1.5% to 3.0%, and inflow rate of alginate was varied from 10 mL/hr to 40 mL/hr. CO2 flow rate was regulated from 2.0 L/min to 4.0 L/min. Viability was checked by dithizone and FDA/PI staining. Secretory function was tested with glucose challenge and insulin stimulation index was investigated. RESULTS: The optimal conditions for islet encapsulation were revealed with alginate inflow rate of 10 mL/hr, CO2 flow rate of 2.0 L/min in concentration of 2% alginate. In concentration of 2.5% alginate, alginate inflow rate of 20 mL/hr, CO2 flow rate 3.0 L/min was ideal, and alginate inflow rate of 40 mL/hr, CO2 flow rate of 4.0 L/min showed good conditions of microcapsules in concentration of 3% alginate. Viability of encapsulated islets was higher than 90% in both rat and porcine. In terms of insulin secretion, encapsulated islets secreted insulin in response to glucose in static culture medium. However there was no normal response to low and high glucose challenge with stimulation index of less than 2.0. CONCLUSION: Microencapsulation of islets in rat and pig was successful with air-driven droplet generator and alginate in vitro. Further studies about biocompatibility and glucose control in vivo should be followed to be a useful tool for treatment of diabetes mellitus patients in clinical setting.

Alpha-Melanocyte Stimulating Hormone Protects Pancreatic Islet Dysfunction by Peripheral Blood Mononuclear Cells in vitro / 대한이식학회지

PURPOSE: The alpha-melanocyte-stimulating hormone (alpha-MSH) has been shown to interact with various cells of the immune and inflammatory system and down-regulate either the production or the action of the pro-inflammatory cytokines. In this study, we investigated the potential of alpha-MSH on preventing pancreatic islet cell from death and dysfunction by inflammatory cytokines released from peripheral blood mononuclear cells (PBMCs) in rat. METHODS: Rat pancreatic islets were co-cultured with PBMCs, stimulated by phorbol myrstic acid and ionomycin. alpha-MSH was treated to PBMCs for 2 hours before co-culture. Viability and apoptosis of islets were observed by MTT and FACS. Inflammatory cytokines and nitric oxide (NO) were measured. Insulin release from islet co-cultured with mononuclear cells was checked for the islet function. RESULTS: In comparison to control group, viability of islets with alpha-MSH treated mononuclear cells was increased and apoptosis was reduced significantly. Inflammatory cytokines such as TNF-alpha and IL-1beta were reduced in alpha-MSH-treated group. NO production in alpha-MSH-treated group was decreased. Insulin secretory function of islet was recovered in condition of alpha-MSH treatment. CONCLUSION: This study demonstrates that alpha-MSH protects cell death and preserves the secretory function of pancreatic islet cells from the pro-inflammatory reaction of mononuclear cells, and may have the potential to improve the graft survival in clinical islet transplantation.

Impact of Cobra Venom Factor on Immunologic Reaction in Rat Xenograft / 대한면역학회지

Recently xenotransplantation has been thought as a final solution for the controi of donor organ shortage in allograft. In order to be a ciinicai entity, xenotransplantation has many obstacles such as hyperacute rejection and delayed xenogratt rejection as a potent immunologic reaction, zoonosis and ethical problems. We already reported the eariy immunoiogic events occuring soon after xenograft in animal model, in which natural antibody and complement have a crucial roie in rejection response. As a further step for the prolongation of graft survival, we used anticomplement agent (cobra venom factor, CVF) in the same model. Graft survival in discordant (guinea pig-to-rat) xenogratt was extended from 30.6 minutes to 2 days following singie injection of CVF, which showed similar pattern of rejection with the concordant xenogratt in terms of time of rejection response after grafting. In this setting antibody response in the blood did not show any difference between that of pre CVF and post CVF, even though IgM response was more pronounced than IgG. The complement activity in the blood showed marked suppression following CVF injection. Intragraft complement gene (C3 mRNA) expression in CVF injected discordant showed delayed response in a similar pattern like that of concordant xenograft. Interestingly enough intragraft anticomplement gene expression showed the simiiar pattern of response with the complement. From these results we can conclude that anticomplement agent (CVF) extended the graft survival in discordant xenograft upto the level of concordant xenograft by shifting the complement activation response from that of discordant to concordant xenograft.