Up-Regulation of HMGB1 Exacerbates Renal Ischemia-Reperfusion Injury by Stimulating Inflammatory and Immune Responses through the TLR4 Signaling Pathway in Mice.

BACKGROUND/AIMS: The aim of this study was to elucidate how high-mobility group box 1 (HMGB1) exacerbates renal ischemic-reperfusion injury (IRI) by inflammatory and immune responses through the toll-like receptor 4 (TLR4) signaling pathway. METHODS: A total of 30 wild-type (WT) mice and 30 TLR4 knockout (TLR4-/-) mice were selected and then randomly assigned to the Sham, I/R or HMGB1 groups. The serum and kidney tissues of all mice were collected 24 h after the perfusion. The fully automatic biochemical detector and ELISA were applied to determine the blood urea nitrogen (BUN) and serum creatinine (Scr) levels, and TNF-α, IL-1ß, IL-6, IFN-γ and IL-10 levels, respectively. HE staining was used to evaluate kidney tissue damage, immunofluorescence and immunohistochemical staining were performed to observe CD68 and MPO cell infiltration, and flow cytometry was applied to detect immune cells. qRT-PCR and Western blotting were used to detect the expressions of TLR signaling pathway-related genes and proteins, respectively. RESULTS: Compared with the Sham group, the levels of BUN, Scr, TNF-α, IL-1ß, IL-6, IFN-γ and IL-10, kidney tissue damage score, CD68 and MPO cell infiltration, the numbers of immune cells, and the expressions of TLR signaling pathway-related genes and proteins in the I/R and HMGB1 groups were significantly up-regulated. In the I/R and HMGB1 groups, the levels of BUN and Scr, TNF-α, IL-1ß, IL-6 and IFN-γ, kidney tissue damage score, CD68 and MPO cell infiltration, immune cell numbers, and TLR signaling pathway-related gene and protein expressions in the WT mice were all higher than those in the TLR4-/- mice, but IL-10 level was significantly lower. Similarly, all aforementioned indexes but IL-10 level in the WT and TLR4-/- mice were higher in the HMGB1 group than in the I/R group. CONCLUSION: Our study indicated that the up-regulation of HMGB1 could exacerbate renal IRI by stimulating inflammatory and immune responses through the TLR4 signaling pathway.c.

Kidney transplantation from donors with rhabdomyolysis and acute renal failure.

Rhabdomyolysis in deceased donors usually causes acute renal failure (ARF), which may be considered a contraindication for kidney transplantation. From January 2012 to December 2016, 30 kidneys from 15 deceased donors with severe rhabdomyolysis and ARF were accepted for transplantation at our center. The peak serum creatinine (SCr) kinase, myoglobin, and SCr of the these donors were 15 569±8597 U/L, 37 092±42 100 µg/L, and 422±167 µmol/L, respectively. Two donors received continuous renal replacement therapy due to anuria. Six kidneys exhibited a discolored appearance (from brown to glossy black) due to myoglobin casts. The kidney transplant results from the donors with rhabdomyolysis donors were compared with those of 90 renal grafts from standard criteria donors (SCD). The estimated glomerular filtration rate at 2 years was similar between kidney transplants from donors with rhabdomyolysis and SCD (70.3±14.6 mL/min/1.73 m2 vs 72.3±15.1 mL/min/1.73 m2 ). We conclude that excellent graft function can be achieved from kidneys donors with ARF caused by rhabdomyolysis.

Renal Transplantation Using Stone-bearing Deceased Donor Kidneys-Experience of a Transplant Center in China.

OBJECTIVE: To evaluate the outcomes of transplantation of deceased donor stone-bearing kidneys. METHODS: A total of 32 patients who received renal transplantation at our center from July 2011 to June 2016 were included. Eight recipients received kidneys with incidental renal stone(s) (stone group). Twenty-four recipients received kidneys without renal stones (non-stone group). The transplantation outcomes of the 2 groups were compared. RESULTS: There was 1 case of postoperative urinary tract infection in the stone group, and 2 cases in the non-stone group. No ureteral obstruction or hydronephrosis occurred in either group. No significant difference was found in the incidence of complications, serum creatinine level, and estimated glomerular filtration rate between the groups (all, P >.05). No deaths occurred in either group during the follow-up period. One recipient had postoperative calculi recurrence, and 4 recipients had residual calculi before transplantation. However, these patients had no symptomatic nephrolithiasis or obstruction, and their renal functions were normal. CONCLUSION: Transplantation of deceased donor stone-bearing kidneys can achieve comparable outcomes of deceased donor non-stone-bearing kidneys.

MicroRNA-423-5p facilitates hypoxia/reoxygenation-induced apoptosis in renal proximal tubular epithelial cells by targeting GSTM1 via endoplasmic reticulum stress.

It has been reported that microRNAs (miRs) can regulate renal response to acute injury and members of them are believed to be important in maintenance of renal function and development of renal injury. We investigated the actions of microRNA-423-5p (miR-423-5p) and glutathione-S-transferase (GST) M1 after acute kidney injury. MiR-423-5p was up-regulated and GSTM1 was down-regulated in human kidney (HK-2) cells subjected to hypoxia/reoxygenation (H/R) and in rat kidneys subjected to ischemia/reperfusion (I/R) injury. Dual luciferase assays revealed miR-423-5p binding to the 3' untranslated region of GSTM1. Proliferation was lower and apoptosis, ER stress and oxidative stress were all higher in H/R-treated HK-2 cells transfected with or without miR-423-5p mimics and GSTM1 siRNA than in the same cells transfected with miR-423-5p inhibitors and a GSTM1 expression vector. Increased miR-423-5p and decreased GSTM1 mRNA and protein levels were observed in rat kidneys on days 1, 2 and 7 after I/R. Levels had normalized by days 14 and 21. On day 3 after treatment, rats receiving I/R or I/R plus miR-423-5p mimics exhibited higher serum creatinine and urea nitrogen levels than rats receiving I/R plus a miR-423-5p inhibitor. MiR-423-5p and lower GSTM1 mRNA and protein levels were higher in the I/R and I/R plus miR-423-5p mimic groups than in the I/R plus miR-423-5p inhibitors group. These findings demonstrate that after acute kidney injury, miR-423-5p induces ER stress and oxidative stress by inhibiting GSTM1and suppresses repair.

MicroRNA-34a regulates liver regeneration and the development of liver cancer in rats by targeting Notch signaling pathway.

OBJECTIVE: This study aimed to investigate the role of microRNA-34a (miR-34a) in regulating liver regeneration (LR) and the development of liver cancer in rats by targeting Notch signaling pathway. METHODS: Thirty male Sprague-Dawley (SD) rats were randomly assigned into partial hepatectomy (PH) group and sham hepatectomy (SH) group. Hematoxylin and eosin (HE) staining was used to observe the histological change in liver tissues. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) levels. Dual-luciferase reporter gene assay was performed to examine whether miR-34a targeted Notch1 gene. Human liver cancer Huh7 cells were transfected and divided into blank, negative control (NC), miR-34a mimics and miR-34a inhibitors groups. MTT and flow cytometry were used to detect cell growth, and cell cycle and apoptosis, respectively. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied detect to the expressions of miR-34a and Notch receptor mRNA. Western blotting was performed to detect the protein expressions of Notch receptors, P21, Bax, Bcl-2 and Bcl-xL. Tumor xenograft in nude mice was done to observe tumor formation in different groups. RESULTS: Compared to the SH group, miR-34a expression in liver tissues in the PH group decreased first and then increased to the normal level during LR. In early stage of LR, the expressions of Notch receptors and miR-34a were negatively correlated. Compared to the blank and NC groups, the cell growth was inhibited, cell cycle was mainly arrested in the G2/M phase and cell apoptosis rate increased in the miR-34a mimics group. Moreover, the expressions of miR-34a, P21 and Bax were up-regulated, while the expressions of Notch receptors, and Bcl-2 and Bcl-xL were down-regulated in this group. Additionally, the tumor growth in the miR-34a mimics group was reduced. The miR-34a inhibitors group showed contrary tendencies. CONCLUSION: Our study demonstrates that miR-34a regulated LR and the development of liver cancer by inhibiting Notch signaling pathway.

One center's experiences of 101 cases of kidney transplants from cardiac death donors.

OBJECTIVES: In 2011, a pilot program of organ donation after cardiac death was begun at the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China, where we hosted one of the largest donation after cardiac death organ transplant programs in the country. We report our initial single-center experiences of kidney transplant from donation after cardiac deaths. MATERIALS AND METHODS: From January 2011 to July 2013 at our center, 101 kidney transplants from donation after cardiac death donors were performed. The results of kidney transplants from donation after cardiac death donors were compared with those of 50 kidney transplants from donation after brain death performed during the same time. RESULTS: Delayed graft function occurred more frequently in donation after cardiac death than donation after brain death kidneys (16.8% vs 4.0%; P = .035). There was no difference in the incidence of acute rejection between donation after cardiac death and donation after brain death kidneys (10.9% vs 6.0%). Actual 1-year graft survival rate was similar (donation after cardiac death 94.4% vs donation after brain death 96.2%). Estimated glomerular filtration rate at 12 months was similar between donation after cardiac death and donation after brain death kidneys (73.8 ± 20.0 vs 77.8 ± 22.7 mL/min/1.73 m2). CONCLUSIONS: Kidney transplants from donation after cardiac death donors have comparable short-term outcomes to kidney transplants from donation after brain death donors. Donation after cardiac death can play a crucial role in overcoming the organ shortage in China.