Supramolecular Nano-Assembly of Caffeate-Strengthened Phenylboronic Ester with Multistep ROS Scavenging Ability for Targeted Therapy of Acute Kidney Injury.

Acute kidney injury (AKI) is a life-threatening complication with a considerable occurrence among patients. AKI is typically accompanied by an elevation in reactive oxidative species (ROS) in renal tissues, which is the main contributor to kidney damage. Herein, a supramolecular nano-assembly (Ser-HPEC) containing an ethyl caffeate-strengthened phenylboronic ester with ROS-triggered antioxidative ability is proposed for AKI-targeted therapy. Nano-assemblies can rapidly accumulate in the ischemia-reperfusion-injured kidney via kidney injury molecule-1 (Kim-1)-mediated homing ability of l-serine. By consuming pathological levels of ROS, two different antioxidants, ethyl caffeate and 4-hydroxybenzyl alcohol, are spontaneously released from a single module to relieve oxidative stress and diminish acute inflammation in injured renal tissue. The multistep ROS scavenging strategy combined with a precise targeting capability endows the aforementioned nano-assembly with effectiveness in preserving the integrity and functions of the injured kidney, providing new inspiration for the treatment of inflammatory diseases, including AKI.

Urinary RBP as an Independent Predictor of Renal Outcome in Diabetic Nephropathy.

Background: Renal tubular impairment is prevalent in diabetic nephropathy (DN) and the histological severity predicted renal outcome. Biomarkers of tubular injury also increased in the urine of DN patients. The retrospective study aimed to assess the prognostic value of clinically widely applied urinary tubular injury markers, retinol-binding protein (RBP), ß2-microglobulin (ß2-MG) and N-acetyl-ß-D-glucosaminidase (NAG) in DN. Method: A total of 305 patients with biopsy-proven DN were enrolled. The baseline urine total protein and components including albumin, IgG, RBP, ß2-MG and NAG were retrieved from medical records. The primary outcome was end stage renal disease (ESRD). Cox proportional hazard analysis and restricted cubic splines were performed to evaluate the association of parameters with ESRD. Nomograms were constructed and concordance index (C-index) was used to measure the prediction ability. Result: The levels of urinary RBP, ß2-MG and NAG were positively correlated with the severity of interstitial fibrosis and tubular atrophy (IFTA). Positive correlations were also observed among ß2-MG, NAG and mesangial expansion. Urinary RBP was not correlated with any glomerular lesions. Urinary RBP, ß2-MG and NAG were risk factors for ESRD in hazard analysis with adjustment for age, gender and body mass index (BMI). The hazard ratios increased with the increment of baseline levels. In the multivariate Cox model including serum creatinine (SCr), total urinary protein, urinary albumin, urinary IgG and the tubular injury biomarkers, urinary RBP (with every g/mol.Cr increase: HR 1.06, 95% CI 1.03-1.10, p =0.001) remained as an independent risk factor for ESRD in DN patients. Patients were divided by the medium value of urinary RBP into the low RBP and high RBP groups. Survival analysis showed that significantly more patients in the high RBP progressed to ESRD compared to those in the low RBP group (p =0.02) when urinary total protein was less than 3.5 g/g. The C-index of the nomogram incorporating age, gender, BMI, SCr and total urine protein was 0.757. The value increased to 0.777 after adding urinary RBP to the model. Conclusions: Urinary RBP excretion was only correlated with the severity of IFTA and independently predicted ESRD in DN patients.

Changes of gut microbiota in diabetic nephropathy and its effect on the progression of kidney injury.

PURPOSE: We aimed to illustrate gut microbiota and short chain fatty acid (SCFA) levels in diabetic nephropathy (DN) patients, and investigate the mechanism of sodium butyrate in diabetic mellitus (DM) rats. METHODS: Gut microbiota and serum SCFA levels were measured by 16S rDNA and GC-MS. After being built by streptozotocin (DM rats), the DM rats were administered 300 mg/kg sodium butyrate for 12 weeks (DM + BU rats). Gut microbiota, serum and fecal butyrate level were measured. RT-PCR, WB and transmission electron microscopy were performed to explore LC3mRNA or LC3B protein expression, and autophagosomes in kidney tissues. AMPK/mTOR protein expression in renal tissue were also measured. RESULTS: The gut microbial dysbiosis was found in DM and DN groups, and some SCFAs-producing bacteria were decreased in DN group. The serum butyrate concentrations were lower in SCFA-DN group compared with SCFA-HC group and SCFA-DM group in the other cohort. Serum butyrate level was positively correlated with eGFR. Sodium butyrate increased serum and fecal butyrate levels, and improved the enlargement of glomerular area and fibronectin and collagen IV expressions in renal tissues in DM + BU rats. The LC3 mRNA, LC3BII/I ratio and number of autophagosomes were increased in renal tissue of DM + BU rats. Higher p-AMPK/AMPK ratio and lower p-mTOR/ mTOR ratio were shown in renal tissue of DM + BU rats compared with DM rats. CONCLUSIONS: We found the decrease in SCFAs-producing bacteria and low SCFAs concentrations in DN patients. Oral butyrate supplementation may improve kidney injury in DM rats, possibly by increasing autophagy via activating AMPK/mTOR pathway.

Mannose-binding lectin activates the nuclear factor-κB and renal inflammation in the progression of diabetic nephropathy.

Increased serum mannose-binding lectin (MBL) level has been proven to correlate with the development of diabetic nephropathy (DN). Here, we aim to find the role and mechanism of MBL involved in the progression of DN. Patients with DN were recruited and divided into two groups according to different rs1800450 genotypes of the MBL2 gene, and inflammatory profiles in monocytes/macrophages were compared between the two groups. MBL was given to treat macrophages, HK2, and HMC, and a co-culture transwell system was then employed. Renal inflammation and fibrosis parameters were measured after knocking down or overexpressing MBL genes in mice. Proinflammatory profile, manifesting as enhanced IL-1ß production and M1 polarization, was found in monocytes/macrophages from DN with a rs1800450 GG genotype of MBL2 gene who had higher MBL level, compared with those with a rs1800450 GA genotype. In mechanism, MBL directly induced inflammatory responses in macrophages, which promoted inflammatory and fibrotic markers in HK2 and HMCs during co-culture. Further experiments showed that MBL can promote macrophages transforming to the M1 subset mainly by activating the nuclear factor-κB pathway. After downregulation of MBL, the blood glucose, triglyceride, urine protein, injuries of glomerulus and tubules, and the degree of renal inflammation and fibrosis were ameliorated in db/db mice treated with AAV-MBL1/2-shRNA. Overexpression of MBL promoted macrophage infiltration in the kidney. In conclusion, MBL is a crucial mediator in the progression of DN via activating the nuclear factor-κB pathway in macrophages. This will serve as a genetic base for some patients with DN who have poor outcomes and provide a direction for the screening.

Performance of the 2019 EULAR/ACR systemic lupus erythematosus classification criteria in a cohort of patients with biopsy-confirmed lupus nephritis.

OBJECTIVE: To evaluate the performance of the European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) SLE classification criteria in a cohort of patients with biopsy-confirmed lupus nephritis (LN) and their renal prognosis. METHODS: Patients with newly diagnosed SLE attending and followed up for >12 months were included. A retrospective review of all patients with renal biopsy fulfilling a consensus expert opinion during 2014 and 2018. Clinical, serological and pathological data were collected and each patient was assigned a high/low criteria scores (HS/LS) group. Survival curves for flare adjusted for multiplicity on renal flares, was applied to the two groups. RESULTS: Applying EULAR/ACR criteria in our cohort of 126 patients, 6 (4.76%) did not meet the criterion, resulting in a sensitivity of 95.24%. The EULAR/ACR criteria scores was positively correlated with SLE disease activity index scores. Additionally, we noticed that a significant difference in clinical and immunological manifestations between HS and LS group. We observed a higher proportions of class Ⅲ or Ⅳ LN and lower proportions of class Ⅱ or V LN (p=0.034) and pathological higher activity index in HS group (p=0.007). Compared with LS groups, patients involved more severe renal damage and achieved higher rate of complete remission in the HS group. The Kaplan-Meier exploratory analyses, adjusted for LN classification, estimated glomerular filtration rate, activity index and chronicity index and induction and maintenance treatments, showed that patients in the HS group had a tendency of higher renal flare risk than that in the LS group (HR=0.21, p=0.04). CONCLUSIONS: The EULAR/ACR criteria performed high sensitivity in identifying SLE in this cohort of biopsy-confirmed LN. Patients with LN with high criteria scores had more extrarenal manifestations, and worse renal prognosis in the short and long terms.

Combination of mesenchymal stromal cells and machine perfusion is a novel strategy for organ preservation in solid organ transplantation.

Organ preservation is a prerequisite for an urgent increase in the availability of organs for solid organ transplantation (SOT). An increasing amount of expanded criteria donor (ECD) organs are used clinically. Currently, the paradigm of organ preservation is shifting from simple reduction of cellular metabolic activity to maximal simulation of an ex vivo physiological microenvironment. An ideal organ preservation technique should not only preserve isolated organs but also offer the possibility of rehabilitation and evaluation of organ function prior to transplantation. Based on the fact that mesenchymal stromal cells (MSCs) possess strong regeneration properties, the combination of MSCs with machine perfusion (MP) is expected to be superior to conventional preservation methods. In recent years, several studies have attempted to use this strategy for SOT showing promising outcomes. With better organ function during ex vivo preservation and the potential of utilization of organs previously deemed untransplantable, this strategy is meaningful for patients with organ failure to help overcome organ shortage in the field of SOT.

Diagnostic roles of urinary kidney microvesicles in diabetic nephropathy.

BACKGROUND: The pathology of diabetic nephropathy (DN) broadly involves the injury of glomeruli, tubulointerstitium and endothelium. Cells from these compartments can release increased numbers of microvesicles (MVs) into urine when stressed or damaged. Currently whether urinary MVs from these three parts can help diagnose DN and reflect pathological features remain unclear. METHODS: Forty-nine patients with histologically proven DN and 29 proteinuric controls with membranous nephropathy or minimal change disease were enrolled. Urinary podocyte, proximal tubular and endothelial cell-derived MVs were quantified by flow cytometry. Renal glomerular, tubulointerstitial and vascular lesions were semi-quantitatively scored and their relevance to urinary MVs were analyzed. RESULTS: DN patients had greater numbers of urinary MVs from podocytes, proximal tubular and endothelial cells compared with proteinuric controls. The combination of podocyte nephrin+ MVs and diabetic retinopathy optimally diagnose DN with 89.7% specificity and 88.9% sensitivity. Moreover, positive correlations were observed between urinary levels of proximal tubular MVs and the severity of tubular injury and between urinary levels of endothelial MVs and the degree of vascular injury. Using urinary proximal tubular MVs as the indicators for tubular injury, the differences between DN patients and proteinuric controls diminished after matching the degree of renal vascular injury or when proteinuria >8 g/24 h. CONCLUSIONS: Urinary kidney-specific cell-derived MVs might serve as noninvasive biomarkers for the diagnosis of DN in diabetic proteinuric patients. Their elevated levels could reflect corresponding renal pathological lesions, helping physicians look into the heterogeneity of DN.

Identification of Key Genes of Human Advanced Diabetic Nephropathy Independent of Proteinuria by Transcriptome Analysis.

BACKGROUND: Diabetic nephropathy (DN) is the leading cause of ESRD. Emerging evidence indicated that proteinuria may not be the determinant of renal survival in DN. The aim of the current study was to provide molecular signatures apart from proteinuria in DN by an integrative bioinformatics approach. METHOD: Affymetrix microarray datasets from microdissected glomerular and tubulointerstitial compartments of DN, healthy controls, and proteinuric disease controls including minimal change disease and membranous nephropathy were extracted from open-access database. Differentially expressed genes (DEGs) in DN versus both healthy and proteinuric controls were identified by limma package, and further defined by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Hub genes were checked by protein-protein interaction networks. RESULTS: A total of 566 glomerular and 581 tubulointerstitial DEGs were identified in DN, which were commonly differentially expressed compared to normal controls and proteinuric disease controls. The upregulated DEGs in both compartments were significantly enriched in GO biological process associated with fibrosis, inflammation, and platelet dysfunction, and largely located in extracellular space, including matrix and extracellular vesicles. Pathway analysis highlighted immune system regulation. Hub genes of the upregulated DEGs negatively correlated with estimated glomerular filtration rate (eGFR). While the downregulated DEGs and their hub genes in tubulointerstitium were enriched in pathways associated with lipid metabolism and oxidation, which positively correlated with eGFR. CONCLUSIONS: Our study identified pathways including fibrosis, inflammation, lipid metabolism, and oxidative stress contributing to the progression of DN independent of proteinuria. These genes may serve as biomarkers and therapeutic targets.

A review of the application of nanoparticles in the diagnosis and treatment of chronic kidney disease.

Chronic kidney disease (CKD) poses a great burden to global public health as current therapies are generally ineffective. Early detection and effective therapy are crucial for the future prevention and progression of CKD. Nanoparticles (NPs) vary by particle size, charge, shape and the density of targeting ligands and are associated with enhancement of the pharmacokinetic properties, targetability, or the bioavailability of drugs. Thus, the emergence of NPs in medicine has provided novel solutions to the potential diagnosis and treatment of CKD. This review describes the current experimental research, clinical applications of NPs, the current challenges, and upcoming opportunities in the diagnosis and treatment of CKD.

Preconditioning is an effective strategy for improving the efficiency of mesenchymal stem cells in kidney transplantation.

The inevitable side effects caused by lifelong immunosuppressive agents in kidney transplantation patients spurred the exploration of novel immunosuppressive strategies with definite curative effects and minimal adverse effects. Mesenchymal stem cells (MSCs) have become a promising candidate due to their role in modulating the immune system. Encouraging results obtained from experimental models have promoted the translation of this strategy into clinical settings. However, the demonstration of only marginal or transient benefits by several recent clinical controlled studies has made physicians hesitant to adopt the routine utilization of this procedure in clinical settings. Impaired MSC function after infusion in vivo was thought to be the main reason for their limited effects. For this reason, some preconditioning methods were developed. In this review, we aim to outline the current understanding of the preconditioning methods being explored as a strategy to improve the therapeutic effects of MSCs in kidney transplantation and promote its clinical translation.

The Crescentic Implication of Renal Outcomes in Proliferative Lupus Nephritis.

OBJECTIVE: To determine the association between crescents and renal outcomes, and the implications on therapeutic choices. METHODS: There were 231 patients with biopsy-proven proliferative lupus nephritis (PLN) who were divided into 4 groups: 59 patients were in the noncrescent group (NC); 59 patients exclusively with segmental crescents were in the segmental crescent group (SC); patients with circumferential crescents were categorized into 2 groups according to the crescentic ratio (C1 had 64 patients with ≤ 25%, and C2 had 49 patients with > 25%). Their baseline laboratory tests, histopathological manifestations, and outcomes were compared. RESULTS: Remission rates in NC, SC, C1, and C2 groups were 92.1%, 85.4%, 95.0%, and 76.1%, respectively. Fewer patients in the C2 group achieved complete remission than the other 3 groups. For longterm outcomes evaluated by serum creatinine (SCr) doubling or endstage renal disease (ESRD), the renal survival rate was lowest in the C2 group (p = 0.003). Including clinical and pathological variables in the Cox proportional hazard regression model separately, the multivariate analysis revealed that these were independent risk factors for SCr doubling or ESRD: baseline SCr (with every 1 mg/dl increase: HR = 1.834, 95% CI 1.465-2.296; p < 0.001), hemoglobin (with every 1 g/l increase: HR = 0.970, 95% CI 0.947-0.992; p = 0.009), the proportions of cellular crescents (with every 1% increase: HR = 1.040, 95% CI 1.015-1.066; p = 0.002) and fibrocellular crescents (with every 1% increase: HR = 1.085, 95% CI 1.013-1.163; p = 0.020), and severe renal tubular atrophy (HR = 5.348, 95% CI 1.278-22.373; p = 0.022). CONCLUSION: PLN with crescents > 25% had worse renal outcomes both in short and long terms. Proportions of cellular and fibrocellular crescents were independent risk factors for poor renal survival.