Objective To analyze the incidence and risk factors of de novo malignant tumors in renal transplant recipients. Methods Clinical data of 1 549 renal transplant recipients were retrospectively analyzed, including the basic status, pathological type and incidence rate of patients with de novo malignant tumors after renal transplantation. The survival situation of these patiensts was assessed. And the risk factors of de novo malignant tumors after renal transplantation were identified. Results The incidence rate of de novo malignant tumors in renal transplant recipients was 3.03%(47/1 549). The 47 recipients were (48±12) years old when undergoing renal transplantation, and they were (55±12) years old when diagnosed malignant tumors. The time interval between transplantation and diagnosis was 66 (36, 100) months. Among the de novo malignant tumors, colorectal cancer was the most common, with a cumulative incidence rate (CIR) of 0.58%. The survival time of 47 recipients with de novo malignant tumors after renal transplantation was 59 (2, 135) months, and the 5-year survival rate was 50%. The recipients with the age > 45 years old when undergoing renal transplantation was a risk factor for de novo malignant tumors after renal transplantation (P < 0.05). Conclusions The incidence rate of de novo malignant tumors is relatively high in renal transplant recipients. The recipients with the age > 45 years old when undergoing renal transplantation is a risk factor for de novo malignant tumors.

Ischemia-reperfusion injury(IRI)and rejection are the main factors affecting the long-term survival of transplant kidneys.IRI or rejection reactions can cause endoplasmic reticulum stress(ERS)leading to renal injury.X-box binding protein 1(XBP1),as the main ERS-related protein regulating cell homeostasis,generates spliced XBP1 after splicing introns by inositol-requiring enzyme 1α(IRE1α),thereby affecting the expression of target genes and reshaping the cell environment.Appropriate ERS can promote cell survival.However,when the threshold is exceeded,excessive expression of XBP1 can lead to cell instability or death,thereby causing an imbalance in the renal internal environment,which is related to the pathogenesis and progression of kidney transplant-related injury.Therefore,the effective activation of XBP1 has a protective effect on stress injury and helps maintain the vitality and integrity of the renal system.This article reviews the ERS pathway IRE1α-XBP1,the role of XBP1 in renal parenchymal cells and immune cells,the role of XBP1 in renal ischemic injury and rejection,and the clinical detection and potential therapies targeting XBP1.It explores the potential value of targeting XBP1 in kidney transplant-related injury,aiming to provide new targets and directions for improving the prognosis of kidney transplantation.

Objective:To explore the safety and feasibility of optimized pathological evaluation system of donor's kidney and modified surgery during adult dual kidney transplantation(DKT)and evaluate its effectiveness to provide more alternative protocols for kidney transplantation from extended criteria donors.Methods:DKT was performed in 10 recipients using the same protocol from June 2019 to May 2021.And retrospective reviewing was performed for clinical data, including characteristics of donors and recipients, optimized pathological evaluation system, modified surgery, treatment regimens, complications and follow-ups.Results:There were 8 male and 2 female donors with an age of(57.9±12.8)years and BMI(24.1±4.1)kg/m 2.The percentage of DCD was 70% and DBD 30%.The serum creatinine before procurement was 107.6(93.3-163.5)μmol/l.Zero-point puncture biopsy was performed for both kidneys and optimized pathological evaluation system was implemented(Banff criteria & Remuzzi score). The pathological results indicated that glomerular sclerosis for left and right kidneys were 2.0(1.5-2.0)and 1.5(1.0-2.0). And Remuzzi score for left and right kidneys were(4.4±1.2)and(3.6±1.5)points respectively.All recipients were male with an age of(43.1±9.0)years and BMI(22.2±1.9)kg/m 2.All PRAs were negative pre-operation.Modified surgery was performed in all recipients(two kidneys were implanted outside iliac vessels without patch and artery of superior kidney was anastomosed to internal iliac artery). Operative duration was(195±54.3)min and serum creatinine before discharge 125.0(102.0-199.0)μmol/L.Renal dynamic scintigraphy indicated that glomerular filtration rate was(30.0±8.2)ml/min for left kidney and(29.2±13.9)ml/min for right kidney.MRA results indicated that morphologies of renal arteries and veins were regular.The time between operation and discharge was(22.4±4.7)days.Compared with SKT, serum creatinine before discharge of DKT was lower and DGF incidence of DKT was higher without statistical significance.The time between operation and discharge was longer for DKT than that for SKT( P<0.05). The complications consisted of 20% donor derived infection(DDI)and 50% DGF.And there was no surgical complication associated with vessels and ureter.Renal function remained stable during 6-month follow-ups. Conclusions:Optimized pathological evaluation system of donor's kidney and modified surgery during adult dual kidney transplantation are both safe and feasible.The postoperative function of transplanted dual kidney is successfully restored.However, long-term follow-ups are required for evaluating its effectiveness.

Objective To evaluate the effect of glycogen synthase kinase 3β (GSK3β) on hypoxia/reoxygenation (H/R)-induced injury of senescent renal tubular epithelial cell (RTEC) in aged mice and its regulatory mechanism. Methods RTEC were divided into the Young group (young RTEC with normal growth), Old group (aged RTEC induced by Etoposide), Old+Ad-shNC+H/R group [aged RTEC induced by Etoposide and then transfected with adenovirus negative control (Ad-shNC) for H/R treatment], and Old+Ad-shGSK3β+H/R group (aged RTEC induced by Etoposide and then transfected with short-hairpin RNA-expressing adenovirus with targeted silencing GSK3β for H/R treatment), respectively. Apoptosis level and mitochondrial reactive oxygen species level were detected by flow cytometry. Calcium ion level was determined by immunofluorescence staining. The expression and phosphorylation levels of GSK3β, mitochondria-associated endoplasmic reticulum membrane (MAM)-related proteins of inositol 1,4,5-trisphosphate receptor1 (ITPR1), voltage dependent anion-selective channel 1(VDAC1) and glucose-regulated protein 75 (GRP75) were detected by Western blot. The interaction between GSK3β and MAM-related proteins was analyzed by immunoprecipitation. Results Compared with the Young group, the apoptosis, mitochondrial reactive oxygen species and mitochondrial calcium ion levels were higher in the Old group. Compared with the Old group, the apoptosis, mitochondrial reactive oxygen species and mitochondrial calcium ion levels were higher in the Old+Ad-shNC+H/R group. Compared with the Old+Ad-shNC+H/R group, the apoptosis, mitochondrial reactive oxygen species and mitochondrial calcium ion levels were lower in the Old+Ad-shGSK3β+H/R group, and the differences were statistically significant (all P<0.05). Compared with the Young group, the expression levels of ITPR1, GRP75 and GSK3β proteins were up-regulated, the phosphorylation levels of ITPR1 and GRP75 were increased, whereas the total protein and phosphorylation levels of VDAC1 were decreased in the Old group. Compared with the Old group, the expression level of GSK3β protein was unchanged, the total protein and phosphorylation levels of ITPR1 and GRP75 were increased, the expression level of total VDAC1 protein remained unchanged and the phosphorylation level was increased in the Old+Ad-shNC+H/R group. Compared with the Old+Ad-shNC+H/R group, the expression level of GSK3β protein was decreased, the expression levels of total ITPR1, GRP75 and VDAC1 proteins were unchanged, whereas the phosphorylation levels were decreased in the Old+Ad-shGSK3β+H/R group. Immunoprecipitation showed that GSK3β could interact with ITPR1, GRP75 and VDAC1 proteins. Conclusions The expression level of GSK3β is up-regulated in senescent RTEC. Down-regulating GSK3β expression may reduce the phosphorylation level of ITPR1-GRP75-VDAC1 complex, constrain the overload of mitochondrial calcium ion, protect mitochondrial function and mitigate cell damage during reperfusion.

Objective To investigate the role and mechanism of spliced X-box binding protein 1 (XBP1s) in the senescence of primary renal tubular epithelial cells induced by hypoxia/reoxygenation (H/R). Methods Primary renal tubular epithelial cells were divided into the normal control group (NC group), H/R group, empty adenovirus negative control group (Ad-shNC group), targeted silencing XBP1s adenovirus group (Ad-shXBP1s group), empty adenovirus+H/R treatment group (Ad-shNC+H/R group) and targeted silencing XBP1s adenovirus+H/R treatment group (Ad-shXBP1s +H/R group), respectively. The expression levels of XBP1s in the NC, H/R, Ad-shNC and Ad-shXBP1s groups were measured. The number of cells stained with β-galactosidase, the expression levels of cell aging markers including p53, p21 and γH2AX, and the levels of reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) were determined in the Ad-shNC, Ad-shNC+H/R and Ad-shXBP1s+H/R groups. Chromatin immunoprecipitation was employed to verify Sirtuin 3 (Sirt3) of XBP1s transcription regulation, and the expression levels of Sirt3 and downstream SOD2 after down-regulation of XBP1s were detected. Mitochondrial reactive oxygen species (mtROS) were detected by flow cytometry. Results Compared with the NC group, the expression level of XBP1s was up-regulated in the H/R group. Compared with the Ad-shNC group, the expression level of XBP1s was down-regulated in the Ad-shXBP1s group (both P<0.001). Compared with the Ad-shNC group, the number of cells stained with β-galactosidase was increased, the expression levels of p53, p21 and γH2AX were up-regulated, the levels of ROS, MDA and mtROS were increased, the SOD activity was decreased, the expression level of Sirt3 was down-regulated, and the ratio of Ac-SOD2/SOD2 was increased in the Ad-shNC+H/R group. Compared with the Ad-shNC+H/R group, the number of cells stained with β-galactosidase was decreased, the expression levels of p53, p21 and γH2AX were down-regulated, the levels of ROS, MDA and mtROS were decreased, the SOD activity was increased, the expression level of Sirt3 was up-regulated and the ratio of Ac-SOD2/SOD2 was decreased in the Ad-shXBP1s+H/R group (all P<0.05). Conclusions Down-regulation of XBP1s may ameliorate the senescence of primary renal tubular epithelial cells induced by H/R, which probably plays a role through the Sirt3/SOD2/mtROS signaling pathway.

Objective To evaluate the effect of spliced X-box binding protein 1 (XBP1s) on hypoxia/reoxygenation (H/R) injury of mouse renal tubular epithelial cells and unravel underlying mechanism. Methods Mouse renal tubular epithelial cells were divided into adenovirus negative control group (Ad-shNC group), targeted silencing XBP1s adenovirus group (Ad-shXBP1s group), Ad-shNC+H/R group and Ad-shXBP1s+H/R group. The apoptosis level, mitochondrial reactive oxygen activity, mitochondrial membrane potential and mitochondrial calcium ion level were detected in each group. Chromatin immunocoprecipitation followed by sequencing (ChIP-seq) was employed to analyze the binding sites of XBP1s in regulating the inositol 1,4,5-trisphosphate receptor (ITPR) family. The expression levels of XBP1s and ITPR family messenger RNA (mRNA) and protein were determined in each group. Results Compared with the Ad-shNC group, the apoptosis level was higher, mitochondrial reactive oxygen species level was increased, mitochondrial membrane potential was decreased and mitochondrial calcium ion level was elevated in the Ad-shNC+H/R group. Compared with the Ad-shNC+H/R group, the apoptosis level was lower, mitochondrial reactive oxygen species level was decreased, mitochondrial membrane potential was elevated, and mitochondrial calcium ion level was decreased in the Ad-shXBP1s+H/R group (all P<0.05). Compared with the Ad-shNC group, relative expression levels of XBP1s, ITPR1, ITPR2 and ITPR3 mRNAs and proteins were down-regulated in the Ad-shXBP1s group (all P<0.05). Compared with the Ad-shNC group, relative expression levels of XBP1s, ITPR1, ITPR2 and ITPR3 proteins were up-regulated in the Ad-shNC+H/R group. Compared with the Ad-shNC+H/R group, relative expression levels of XBP1s, ITPR1, ITPR2 and ITPR3 were down-regulated in the Ad-shXBP1s+H/R group (all P<0.05). ChIP-seq results showed that XBP1s could bind to the promoter and exon of ITPR1, the exon of ITPR2, and the exon of ITPR3. Conclusions XBP1s may affect mitochondria-associated endoplasmic reticulum membrane structure and function by directly regulating ITPR transcription and translation. Down-regulating XBP1s may inhibit ITPR expression and mitigate mitochondrial damage.