Gut permeability, circulating bacterial fragments and measures of congestion in peritoneal dialysis.

Background: Limited data exist on the association between gut permeability, circulating bacterial fragment and volume overload in peritoneal dialysis (PD) patients. We measured circulating bacterial fragments, N-terminal pro B-type natriuretic peptide (NT-proBNP), calprotectin and zonulin levels, and evaluate their association with the clinical outcomes in PD patients. Methods: This was a single-center prospective study on 108 consecutive incident PD patients. Plasma endotoxin and bacterial DNA, and serum NT-proBNP, calprotectin and zonulin levels were measured. Primary outcomes were technique and patient survival, secondary outcomes were hospitalization data. Results: There was no significant correlation between plasma endotoxin and bacterial DNA, and serum NT-proBNP, calprotectin and zonulin levels. The Homeostatic Model Assessment for Insulin Resistance (HOMA)-2ß index, which represents insulin resistance, positively correlated with plasma bacterial DNA (r = 0.421, P < .001) and calprotectin levels (r = 0.362, P = .003), while serum NT-proBNP level correlated with the severity of volume overload and residual renal function. Serum NT-proBNP level was associated with technique survival even after adjusting for confounding factors [adjusted hazard ratio (aHR) 1.030, 95% confidence interval 1.009-1.051]. NT-proBNP level was also associated with patient survival by univariate analysis, but the association became insignificant after adjusting for confounding factors (aHR 1.010, P = .073). Similarly, NT-proBNP correlated with the number of hospitalizations and duration of hospitalization by univariate analysis, but the association became insignificant after adjusting for confounding factors. Conclusion: There was no correlation between markers of gut permeability, circulating bacterial fragments and measures of congestion in PD patients. Bacterial fragments levels and gut permeability are both associated with insulin resistance. Serum NT-proBNP level is associated with the severity of volume overload and technique survival. Further studies are required to delineate the mechanism of high circulating bacterial fragment levels in PD patients.

Urinary podocyte markers in diabetic kidney disease.

Podocytes are involved in maintaining kidney function and are a major focus of research on diabetic kidney disease (DKD). Urinary biomarkers derived from podocyte fragments and molecules have been proposed for the diagnosis and monitoring of DKD. Various methods have been used to detect intact podocytes and podocyte-derived microvesicles in urine, including centrifugation, visualization, and molecular quantification. Quantification of podocyte-specific protein targets and messenger RNA levels can be performed by Western blotting or enzyme-linked immunosorbent assay and quantitative polymerase chain reaction, respectively. At present, many of these techniques are expensive and labor-intensive, all limiting their widespread use in routine clinical tests. While the potential of urinary podocyte markers for monitoring and risk stratification of DKD has been explored, systematic studies and external validation are lacking in the current literature. Standardization and automation of laboratory methods should be a priority for future research, and the added value of these methods to routine clinical tests should be defined.

The Hippo pathway and its correlation with acute kidney injury.

Acute kidney injury (AKI) is a significant clinical complication with a substantial impact on morbidity and mortality, for which therapeutic options remain limited. The Hippo signaling pathway is an evolutionarily conserved pathway implicated in cell proliferation, dedifferentiation, and apoptosis via phosphorylation and inactivation of its downstream effectors Yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ). Recent studies have revealed that the Hippo pathway plays a pivotal role in the pathogenesis and repair of AKI. The Hippo pathway can mediate renal dysfunction through modulation of mitochondrial apoptosis under AKI conditions. Transient activation of YAP/TAZ in the acute phase of AKI may benefit renal recovery and regeneration, whereas persistent activation of YAP/TAZ in severe AKI may lead to maladaptive repair and transition to chronic kidney disease. This review aims to summarize recent findings on the associations between the Hippo pathway and AKI and to identify new therapeutic targets and strategies for AKI.

Numerical simulation and protection of the dynamic change of Jinan karst spring based on coupling of seepage and conduit flow.

The objective of this study was to predict the dynamic change in the spring water level more precisely, to provide timely solutions for karst spring protection. Using the Jinan spring region as a case study, this study established a numerical model of a karst groundwater system, and optimized the mining layout. The calculated maximum extraction volume following the optimized exploitation layout was 0.69 m3/s, in order to ensure the continuous flow of spring water in the median water year. A coupled karst groundwater numerical model with dual structure was developed using the MODFLOW-Conduit Flow Process (CFP), which simulates and then precisely predicts changes in the water level of the karst springs. Here, the plane extension direction of the karst conduit was determined by a tracer test and correlation analysis of the spring water levels and groundwater levels of the observation wells. Meanwhile, the vertical location of the karst conduit was determined by layered monitoring of the groundwater temperature and conductivity. Based on this, a coupling model of seepage and conduit flow was created to simulate the dynamic change in the spring water level, and the dual-media coupling model improved the simulation accuracy of the spring water level. The current study confirmed that, compared to the porous media seepage model, the dual-media coupling model can simulate the groundwater level dynamic change more accurately in a heterogeneous karst aquifer in northern China. The coupling model was used to analyze the effect of supplementation and optimize mining, to ensure that spring water continues to flow during the dry season while supplying the mining demand.

Hydrochemical environment of a fractured karst aquifer influenced by petroleum hydrocarbons.

A fractured karst aquifer polluted by petroleum hydrocarbons (PH) for several decades was selected to study the influences of PH on the hydrochemical environment. The research was implemented using the hydrochemical indicators (Ca2+, Mg2+, Na++K+, HCO3-, NO3-, Cl-, F-, and SO42-) and PH with the help of GIS and origin platforms, statistical analyses, and graphical methods. Results showed that PH had significant influences on the hydrochemical environment over the last several decades. The main principle elements influencing the evolution processes of hydrochemical environment were carbonates dissolution, leaking wastewater, and biodegradation processes from 1977 to 2019, and hydrochemistry types changed from HCO3-Ca-Mg and HCO3-Ca to HCO3-Cl-Ca-Mg and HCO3-Cl-Ca. The contribution rate of PH biodegradation to the representative ion increased at first, then decreased over time, which has a close relationship with the variation characteristics of PH. The dynamic evolution processes of hydrochemical environment have significances for indentifying the influencing mechanisms of hydrogeochemical reactions, which could provide valuable scientific suggestions for the local administrators to take effective efforts to optimize and protect the karst groundwater environment.

NLRP3 associated with chronic kidney disease progression after ischemia/reperfusion-induced acute kidney injury.

Nod-like receptor protein 3 (NLRP3), as an inflammatory regulator, has been implicated in acute kidney injury (AKI). Failed recovery after AKI can lead to chronic kidney disease (CKD). However, the role of NLRP3 in the AKI-CKD transition is still unknown. A mild or severe AKI mouse model was performed by using ischemia-reperfusion injury (IRI). We evaluated the renal NLRP3 expression in acute and chronic phases of ischemic AKI, respectively. Although serum creatinine (Cr) and blood urea nitrogen (BUN) levels in AKI chronic phase were equivalent to normal baseline, histological analysis and fibrotic markers revealed that severe AKI-induced maladaptive tubular repair with immune cell infiltration and fibrosis. Tubular damage was restored completely in mild AKI rather than in severe AKI. Of note, persistent overexpression of NLRP3 was also found in severe AKI but not in mild AKI. In the severe AKI-induced chronic phase, there was a long-term high level of NLRP3 in serum or urine. Overt NLRP3 was mainly distributed in the abnormal tubules surrounded by inflammatory infiltrates and fibrosis, which indicated the maladaptive repair. Renal Nlrp3 overexpression was correlated with infiltrating macrophages and fibrosis. Renal NLRP3 signaling-associated genes were upregulated after severe AKI by RNA-sequencing. Furthermore, NLRP3 was found increased in renal tubular epitheliums from CKD biopsies. Together, persistent NLRP3 overexpression was associated with chronic pathological changes following AKI, which might be a new biomarker for evaluating the possibility of AKI-CKD transition.

Hypophosphatemia is an independent risk factor for AKI among hospitalized patients with COVID-19 infection.

BACKGROUND: This study sought to investigate incidence and risk factors for acute kidney injury (AKI) in hospitalized COVID-19. METHODS: In this retrospective study, we enrolled 823 COVID-19 patients with at least two evaluations of renal function during hospitalization from four hospitals in Wuhan, China between February 2020 and April 2020. Clinical and laboratory parameters at the time of admission and follow-up data were recorded. Systemic renal tubular dysfunction was evaluated via 24-h urine collections in a subgroup of 55 patients. RESULTS: In total, 823 patients were enrolled (50.5% male) with a mean age of 60.9 ± 14.9 years. AKI occurred in 38 (40.9%) ICU cases but only 6 (0.8%) non-ICU cases. Using forward stepwise Cox regression analysis, we found eight independent risk factors for AKI including decreased platelet level, lower albumin level, lower phosphorus level, higher level of lactate dehydrogenase (LDH), procalcitonin, C-reactive protein (CRP), urea, and prothrombin time (PT) on admission. For every 0.1 mmol/L decreases in serum phosphorus level, patients had a 1.34-fold (95% CI 1.14-1.58) increased risk of AKI. Patients with hypophosphatemia were likely to be older and with lower lymphocyte count, lower serum albumin level, lower uric acid, higher LDH, and higher CRP. Furthermore, serum phosphorus level was positively correlated with phosphate tubular maximum per volume of filtrate (TmP/GFR) (Pearson r = 0.66, p < .001) in subgroup analysis, indicating renal phosphate loss via proximal renal tubular dysfunction. CONCLUSION: The AKI incidence was very low in non-ICU patients as compared to ICU patients. Hypophosphatemia is an independent risk factor for AKI in patients hospitalized for COVID-19 infection.

[Effect of Jiedu Limai decoction in septic patients with syndrome of heat-toxin exuberance].

OBJECTIVE: To investigate the clinical effect of Jiedu Limai decoction in septic patients with syndrome of heat-toxin exuberance. METHODS: A prospective randomized controlled trial was conducted. From March 2019 to April 2020, septic patients with syndrome of heat-toxin exuberance admitted to intensive care unit (ICU) of Shanghai General Hospital and Songjiang Branch of Shanghai General Hospital were enrolled as the research objects, and they were divided into routine treatment group and Jiedu Limai decoction group by the random number table method. Patients in both groups were given standard treatment in accordance with the guidelines, and patients in the Jiedu Limai decoction group were given Jiedu Limai decoction in addition to the standard treatment, once a day for 14 days. The 28-day survival of patients of the two groups were recorded, the acute physiology and chronic health evaluation II (APACHE II) score, sequential organ failure assessment (SOFA) score, coagulation indexes, infection indexes, inflammatory cytokines and organ function indicators before treatment and 7 days after treatment in both groups were recorded, and the prognosis of the two groups were recorded. RESULTS: A total of 259 patients with infection or clinical diagnosis of infection admitted during the experimental observation period were included, and those who did not meet the Sepsis-3 diagnostic criteria, more than 80 years old or less than 18 years old, with multiple tumor metastases, autoimmune system diseases, with length of ICU stay less than 24 hours, with acute active gastrointestinal bleeding and with incomplete data were excluded. One hundred patients were finally enrolled, with 50 patients in the routine treatment group and 50 patients in the Jiedu Limai decoction group. There were no statistically significant differences in coagulation indexes, infection indicators, inflammatory cytokines and organ function indicators before treatment between the two groups. After 7 days of treatment, the coagulation indexes, infection biomarkers and inflammatory cytokines in the Jiedu Limai decoction group were significantly lower than those in the routine treatment group [D-dimer (mg/L): 2.2 (1.8, 8.5) vs. 4.0 (1.5, 8.7), fibrinogen (Fib, g/L): 3.7 (3.4, 4.3) vs. 4.2 (3.7, 4.3), fibrinogen degradation product (FDP, mg/L): 7.2 (5.4, 10.2) vs. 13.2 (9.2, 15.2), procalcitonin (PCT, µg/L): 0.4 (0.2, 2.9) vs. 0.5 (0.2, 0.9), C-reactive protein (CRP, mg/L): 50.1 (9.5, 116.0) vs. 75.1 (23.5, 115.2), interleukin-6 (IL-6, ng/L): 31.6 (21.6, 81.0) vs. 44.1 (14.0, 71.3), all P < 0.05], and the levels of B-type brain natriuretic peptide (BNP) and kidney injury molecule-1 (KIM-1) were significantly lowered [BNP (ng/L): 261.1 (87.5, 360.3) vs. 347.3 (128.8, 439.4), KIM-1 (µg/L): 0.86 (0.01, 1.40) vs. 1.24 (1.05, 1.57), both P < 0.05]. Compared with the routine treatment group, the number of new organ failure in the Jiedu Limai decoction group was decreased (30.0% vs. 50.0%, P < 0.05). Although there was no significant difference in 28-day mortality between the two groups (P > 0.05), the 28-day mortality in the Jiedu Limai decoction group was lower than that in the routine treatment group (18.0% vs. 24.0%). CONCLUSIONS: Combining Jiedu Limai decoction to the sepsis guideline in treating syndrome of heat-toxin exuberance can effectively improve patients' coagulation function, the situation of heart and renal injury, reduce the level of inflammatory cytokines, and fewer people develop new organ failure after treatment.

A validation study of UCSD-Mayo risk score in predicting hospital-acquired acute kidney injury in COVID-19 patients.

INTRODUCTION: Acute kidney injury (AKI) in coronavirus disease 2019 (COVID-19) patients is associated with poor prognosis. Early prediction and intervention of AKI are vital for improving clinical outcome of COVID-19 patients. As lack of tools for early AKI detection in COVID-19 patients, this study aimed to validate the USCD-Mayo risk score in predicting hospital-acquired AKI in an extended multi-center COVID-19 cohort. METHODS: Five hundred seventy-two COVID-19 patients from Wuhan Tongji Hospital Guanggu Branch, Wuhan Leishenshan Hospital, and Wuhan No. Ninth Hospital was enrolled for this study. Patients who developed AKI or reached an outcome of recovery or death during the study period were included. Predictors were evaluated according to data extracted from medical records. RESULTS: Of all patients, a total of 44 (8%) developed AKI. The UCSD-Mayo risk score achieved excellent discrimination in predicting AKI with the C-statistic of 0.88 (95%CI: 0.84-0.91). Next, we determined the UCSD-Mayo risk score had good overall performance (Nagelkerke R2 = 0.32) and calibration in our cohort. Further analysis showed that the UCSD-Mayo risk score performed well in subgroups defined by gender, age, and several chronic comorbidities. However, the discrimination of the UCSD-Mayo risk score in ICU patients and patients with mechanical ventilation was not good which might be resulted from different risk factors of these patients. CONCLUSIONS: We validated the performance of UCSD-Mayo risk score in predicting hospital-acquired AKI in COVID-19 patients was excellent except for patients from ICU or patients with mechanical ventilation.

Hippo-YAP/MCP-1 mediated tubular maladaptive repair promote inflammation in renal failed recovery after ischemic AKI.

Acute kidney injury (AKI) is associated with significant morbidity and its chronic inflammation contributes to subsequent chronic kidney disease (CKD) development. Yes-associated protein (YAP), the major transcriptional coactivator of the Hippo pathway, has been shown associated with chronic inflammation, but its role and mechanism in AKI-CKD transition remain unclear. Here we aimed to investigate the role of YAP in AKI-induced chronic inflammation. Renal ischemia/reperfusion (I/R) was used to induce a mouse model of AKI-CKD transition. We used verteporfin (VP), a pharmacological inhibitor of YAP, to treat post-IRI mice for a period, and evaluated the influence of YAP inhibition on long-term outcomes of AKI. In our results, severe IRI led to maladaptive tubular repair, macrophages infiltration, and progressive fibrosis. Following AKI, the Hippo pathway was found significantly altered with YAP persistent activation. Besides, tubular YAP activation was associated with the maladaptive repair, also correlated with interstitial macrophage infiltration. Monocyte chemoattractant protein 1 (MCP-1) was found notably upregulated with YAP activation. Of note, pharmacological inhibition of YAP in vivo attenuated renal inflammation, including macrophage infiltration and MCP-1 overexpression. Consistently, in vitro oxygen-glucose deprivation and reoxygenation (OGD/R) induced YAP activation and MCP-1 overproduction whereas these could be inhibited by VP. In addition, we modulated YAP activity by RNA interference, which further confirmed YAP activation enhances MCP-1 expression. Together, we concluded tubular YAP activation with maladaptive repair exacerbates renal inflammation probably via promoting MCP-1 production, which contributes to AKI-CKD transition.

Protective effect of taraxasterol on ischemia/reperfusion-induced acute kidney injury via inhibition of oxidative stress, inflammation, and apoptosis.

Ischemia/reperfusion injury (IRI), the most common cause of acute kidney injury (AKI), is correlated with oxidative stress and subsequent inflammation. Taraxasterol, a natural product, has been shown to exert anti-oxidative and anti-inflammatory effects. However, the role of taraxasterol in renal IRI remains unknown. In this study, mice were subjected to 30 min of bilateral renal ischemia-reperfusion to induce AKI. Cellular hypoxia/reoxygenation (H/R) was used to mimic IRI in vitro. Western blotting, immunochemistry, immunofluorescence, TUNEL staining, ELISA, and flow cytometry were performed to evaluate kidney damage, oxidative stress, inflammation, and apoptosis in vivo and in vitro. Treatment with taraxasterol attenuated the following in a dose-dependent manner: tubular damage; infiltration of F4/80-positive macrophages; renal interstitial fibrosis; myeloperoxidase (MPO) activity; and expression of the inflammatory cytokines tumour necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and monocyte chemoattractant protein-1 (MCP-1). Moreover, taraxasterol treatment remarkably ameliorated apoptosis in the kidney by decreasing Bax expression and conserving Bcl2. Notably, MitoSOX assay revealed that treatment with taraxasterol suppressed the production of mitochondrial reactive oxygen species. Furthermore, taraxasterol suppressed phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) of the mitogen-activated protein kinase (MAPK) signaling pathways in vivo and in vitro. In conclusion, these findings indicate that taraxasterol has a protective effect on IRI-induced AKI via inhibition of oxidative stress, inflammation, and apoptosis.