Identification of common and specific fibrosis-related genes in three common chronic kidney diseases

BACKGROUND

Kidney fibrosis is the common final pathway of virtually all advanced forms of chronic kidney disease (CKD) including diabetic nephropathy (DN), IgA nephropathy (IgAN) and membranous nephropathy (MN), with complex mechanism. Comparative gene expression analysis among these types of CKD may shed light on its pathogenesis. Therefore, we conducted this study aiming at exploring the common and specific fibrosis-related genes involved in different types of CKD.

METHODS

Kidney biopsy specimens from patients with different types of CKD and normal control subjects were analyzed using the NanoString nCounter® Human Fibrosis V2 Panel. Genes differentially expressed in all fibrotic DN, IgAN and MN tissues compared to the normal controls were regarded as the common fibrosis-related genes in CKD, whereas genes exclusively differentially expressed in fibrotic DN, IgAN or MN samples were considered to be the specific genes related to fibrosis in DN, IgAN and MN respectively. Quantitative real-time PCR (qRT-PCR) was performed to validate the expression of the selected genes.

RESULTS

Protein tyrosine phosphatase receptor type C (PTPRC), intercellular cell adhesion molecule-1 (ICAM1), vascular cell adhesion molecule-1 (VCAM1), interleukin 10 receptor alpha (IL10RA) and CC chemokine receptor 2 (CCR2) were identified as the potential common genes for kidney fibrosis in different types of CKD, while peroxisome proliferator-activated receptor alpha (PPARA), lactate oxidase (LOX), secreted phosphoprotein 1 (SPP1) were identified as the specific fibrosis-associated genes for DN, IgAN and MN respectively. qRT-PCR demonstrated that the expression levels of these selected genes were consistent with the NanoString analysis.

CONCLUSIONS

There were both commonalities and differences in the mechanisms of fibrosis in different types of CKD, the commonalities might be used as the common therapeutic targets for kidney fibrosis in CKD, while the differences might be used as the diagnostic markers for DN, IgAN and MN respectively. Inflammation was highly relevant to the pathogenesis of fibrosis. This study provides further insight into the pathophysiology and treatment of fibrotic kidney disease.

Hippo pathway activated by circulating reactive oxygen species mediates cardiac diastolic dysfunction after acute kidney injury

Acute kidney injury (AKI) can cause distal cardiac dysfunction; however, the underlying mechanism is unknown. Oxidative stress is proved prominent in AKI-induced cardiac dysfunction, and a possible bridge role of oxidative-stress products in cardio-renal interaction has been reported. Therefore, this study aimed to investigate the critical role of circulating reactive oxygen species (ROS) in mediating cardiac dysfunction after bilateral renal ischemia-reperfusion injury (IRI). We observed the diastolic dysfunction in the mice following renal IRI, accompanied by reduced ATP levels, oxidative stress, and branched-chain amino acids (BCAA) accumulation in the heart. Notably, ROS levels showed a sequential increase in the kidneys, circulation, and heart. Treatment with tempol, an ROS scavenger, significantly restored cardiac diastolic function in the renal IRI mice, corroborating the bridge role of circulating ROS. Accumulating evidence has identified oxidative stress as upstream of Mst1/Hippo in cardiac injury, which could regulate the expression of downstream genes related to mitochondrial quality control, leading to lower ATP, higher ROS and metabolic disorder. To verify this, we examined the activation of the Mst1/Hippo pathway in the heart of renal IRI mice, which was alleviated by tempol treatment as well. In vitro, analysis revealed that Mst1-knockdown cardiomyocytes could be activated by hydrogen peroxide (H2O2). Analysis of Mst1-overexpression cardiomyocytes confirmed the critical role of the Mst1/Hippo pathway in oxidative stress and BCAA dysmetabolism. Therefore, our results indicated that circulating ROS following renal IRI activates the Mst1/Hippo pathway of myocardium, leading to cardiac oxidative stress and diastolic dysfunction. This finding provides new insights for the clinical exploration of improved treatment options for cardiorenal syndrome.

IGFBP2 induces podocyte apoptosis promoted by mitochondrial damage via integrin α5/FAK in diabetic kidney disease

Podocyte apoptosis or loss is the pivotal pathological characteristic of diabetic kidney disease (DKD). Insulin-like growth factor-binding protein 2 (IGFBP2) have a proinflammatory and proapoptotic effect on diseases. Previous studies have shown that serum IGFBP2 level significantly increased in DKD patients, but the precise mechanisms remain unclear. Here, we found that IGFBP2 levels obviously increased under a diabetic state and high glucose stimuli. Deficiency of IGFBP2 attenuated the urine protein, renal pathological injury and glomeruli hypertrophy of DKD mice induced by STZ, and knockdown or deletion of IGFBP2 alleviated podocytes apoptosis induced by high concentration of glucose or in DKD mouse. Furthermore, IGFBP2 facilitated apoptosis, which was characterized by increase in inflammation and oxidative stress, by binding with integrin α5 (ITGA5) of podocytes, and then activating the phosphorylation of focal adhesion kinase (FAK)-mediated mitochondrial injury, including membrane potential decreasing, ROS production increasing. Moreover, ITGA5 knockdown or FAK inhibition attenuated the podocyte apoptosis caused by high glucose or IGFBP2 overexpression. Taken together, these findings unveiled the insight mechanism that IGFBP2 increased podocyte apoptosis by mitochondrial injury via ITGA5/FAK phosphorylation pathway in DKD progression, and provided the potential therapeutic strategies for diabetic kidney disease.

Evidence of decreased long-term risk of cervical pre-cancer after negative primary HPV screens compared to negative cytology screens in a longitudinal cohort study

BACKGROUND

Growing use of primary HPV cervical cancer screening requires determining appropriate screening intervals to avoid overtreatment of transient disease. This study examined the long-term risk of cervical precancer after HPV screening to inform screening interval recommendations.

METHODS

This longitudinal cohort study (British Columbia, Canada, 2008-2022) recruited women and individuals with a cervix (WIC) who received 1-2 negative HPV screen(s) (HPV1 cohort, N = 5,546, HPV2 cohort, N = 6,624) during a randomized trial and WIC with 1-2 normal cytology result(s) (BCS1 cohort, N = 782,297, BCS2 cohort, N = 673,778) extracted from the provincial screening registry. All participants were followed through the registry for 14 years. Long-term risk of cervical precancer or worse (CIN2+) was compared between HPV and cytology cohorts.

RESULTS

Cumulative risks of CIN2+ were 3.2/1000 (95% CI: 1.6 to 4.7) in HPV1 and 2.7/1000 (CI: 1.2 to 4.2) in HPV2 after eight years. This was comparable to the risk in the cytology cohorts after 3 years (BCS1: 3.3/1000, [CI: 3.1 to 3.4]; BCS2: 2.5, [CI: 2.4 to 2.6]). The cumulative risk of CIN2+ after 10 years was low in HPV cohorts (HPV1: 4.7/1000, [CI: 2.6 to 6.7]; HPV2: 3.9, [CI: 1.1 to 6.6]).

CONCLUSIONS

Risk of CIN2+ eight years after negative screen in HPV cohorts was comparable to risk after 3 years in cytology cohorts (the benchmark for acceptable risk).

IMPACT

These findings suggest that primary HPV screening intervals could be extended beyond the current five-year recommendation potentially reducing barriers to screening.

Local Renal Treatments for Acute Kidney Injury: A Review of Current Progress and Future Translational Opportunities

Acute kidney injury (AKI) constitutes a significant public health concern, with limited therapeutic options to mitigate injury or expedite recovery. A novel therapeutic approach, local renal treatment, encompassing pharmacotherapy and surgical interventions, has exhibited positive outcomes in AKI management. Peri-renal administration, employing various delivery routes, such as the renal artery, intrarenal, and subcapsular sites, has demonstrated superiority over peripheral intravenous infusion. This review evaluates different drug delivery methods, analyzing their benefits and limitations, and proposes potential improvements. Renal decapsulation, particularly with the availability of minimally invasive techniques, emerges as an effective procedure warranting renewed consideration for AKI treatment. The potential synergistic effects of combined drug delivery and renal decapsulation could further advance AKI therapies. Clinical studies have already begun to leverage the benefits of local renal treatments, and with ongoing technological advancements, these modalities are expected to increasingly outperform systemic intravenous therapy.

Platelet-rich plasma-derived exosomes enhance mesenchymal stem cell paracrine function and nerve regeneration potential

BACKGROUND

Peripheral nerve injury (PNI) presents a significant clinical challenge, leading to enduring sensory-motor impairments. While mesenchymal stem cell (MSC)-based therapy holds promise for PNI treatment, enhancing its neurotrophic effects remains crucial. Platelet-rich plasma-derived exosomes (PRP-Exo), rich in bioactive molecules for intercellular communication, offer potential for modulating cellular biological activity.

METHODS

PRP-Exo was isolated, and its impact on MSC viability was evaluated. The effects of PRP-Exo-treated MSCs (MSCPExo) on Schwann cells (SCs) from injured sciatic nerves and human umbilical vein endothelial cells (HUVECs) were assessed. Furthermore, the conditioned medium from MSCPExo (MSCPExo-CM) was analyzed using a cytokine array and validated through ELISA and Western blot.

RESULTS

PRP-Exo enhanced MSC viability. Coculturing MSCPExo with SCs ameliorated apoptosis and promoted SC proliferation following PNI. Similarly, MSCPExo-CM exhibited pro-proliferative, migratory, and angiogenic effects. Cytokine array analysis identified 440 proteins in the MSCPExo secretome, with 155 showing upregulation and 6 showing downregulation, many demonstrating potent pro-regenerative properties. ELISA confirmed the enrichment of several angiotrophic and neurotrophic factors. Additionally, Western blot analysis revealed the activation of the PI3K/Akt signaling pathway in MSCPExo.

CONCLUSION

Preconditioning MSCs with PRP-Exo enhanced the paracrine function, particularly augmenting neurotrophic and pro-angiogenic secretions, demonstrating an improved potential for neural repair.

[A survey on the current situation of serum vitamin A and vitamin D levels among children aged 2-<7 years of 20 cities in China]

Objective: To investigate serum vitamin A and vitamin D status in children aged 2-<7 years in 20 cities in China. Methods: A cross-sectional study was conducted. A total of 2 924 healthy children aged 2-<7 years were recruited from September 2018 to September 2019 from 20 cities in China, categorized by age groups of 2-<3 years, 3-<5 years, and 5-<7 years. The demographic and economic characteristics and health-related information of the enrolled children were investigated. Body weight and height were measured by professional staff members. The serum vitamin A and vitamin D levels were detected by high-performance liquid chromatography-tandem mass spectrometry. Chi-square test and Logistic regression were applied to analyze the association between vitamin A and vitamin D deficiency and insufficiency as well as their underlying impact factors. Results: The age of the 2 924 enrolled children was 4.33 (3.42, 5.17) years. There were 1 726 males (59.03%) and 1 198 females (40.97%). The prevalences of vitamin A and vitamin D deficiency in enrolled children were 2.19% (64/2 924) and 3.52% (103/2 924), respectively, and the insufficiency rates were 29.27% (856/2 924) and 22.20% (649/2 924), respectively. Children with both vitamin A and vitamin D deficiencies or insufficiencies were found in 10.50% (307/2 924) of cases. Both vitamin A (χ2=7.91 and 8.06, both P=0.005) and vitamin D (χ2=71.35 and 115.10, both P<0.001) insufficiency rates were higher in children aged 3-<5 and 5-<7 years than those in children aged 2-<3 years. Vitamin A and vitamin D supplementation in the last 3 months was a protective factor for vitamin A and D deficiency and insufficiency, respectively (OR=0.68 and 0.22, 95%CI 0.49-0.95 and 0.13-0.40, both P<0.05). The rates of vitamin A and D insufficiency was higher in children with annual household incomes <60 000 RMB than in those with annual household incomes ≥60 000 RMB (χ2=34.11 and 10.43, both P<0.01). Northwest and Southwest had the highest rates of vitamin A and vitamin D insufficiency in children aged 2-<7 yeas, respectively (χ2=93.22 and 202.54, both P<0.001). Conclusions: Among 20 cities in China, children aged 2-<7 years experience high rates of vitamin A and vitamin D insufficiency, which are affected by age, family economic level, vitamin A and vitamin D supplementation, and regional economic level. The current results suggest that high level of attention should be paid to vitamin A and vitamin D nutritional status of preschool children.

Platelet-rich plasma-derived exosomes boost mesenchymal stem cells to promote peripheral nerve regeneration

Peripheral nerve injury (PNI) remains a severe clinical problem with debilitating consequences. Mesenchymal stem cell (MSC)-based therapy is promising, but the problems of poor engraftment and insufficient neurotrophic effects need to be overcome. Herein, we isolated platelet-rich plasma-derived exosomes (PRP-Exos), which contain abundant bioactive molecules, and investigated their potential to increase the regenerative capacity of MSCs. We observed that PRP-Exos significantly increased MSC proliferation, viability, and mobility, decreased MSC apoptosis under stress, maintained MSC stemness, and attenuated MSC senescence. In vivo, PRP-Exo-treated MSCs (pExo-MSCs) exhibited an increased retention rate and heightened therapeutic efficacy, as indicated by increased axonal regeneration, remyelination, and recovery of neurological function in a PNI model. In vitro, pExo-MSCs coculture promoted Schwann cell proliferation and dorsal root ganglion axon growth. Moreover, the increased neurotrophic behaviour of pExo-MSCs was mediated by trophic factors, particularly glia-derived neurotrophic factor (GDNF), and PRP-Exos activated the PI3K/Akt signalling pathway in MSCs, leading to the observed phenotypes. These findings demonstrate that PRP-Exos may be novel agents for increasing the ability of MSCs to promote neural repair and regeneration in patients with PNI.

Inhibition of HOXD11 promotes cartilage degradation and induces osteoarthritis development

The 5'-HOXD genes are important for chondrogenesis in vertebrates, but their roles in osteoarthritis (OA) are still ambiguous. In our study, 5'-HOXD genes involvement contributing to cartilage degradation and OA was investigated. In bioinformatics analysis of 5'-HOXD genes, we obtained the GSE169077 data set related to OA in the GEO and analyzed DEGs using the GEO2R tool attached to the GEO. Then, we screened the mRNA levels of 5'-HOXD genes by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). We discovered that OA chondrocyte proliferation was inhibited, and apoptosis was increased. Moreover, it was discovered that SOX9 and COL2A1 were downregulated at mRNA and protein levels, while matrix metalloproteinases (MMPs) and a disintegrin-like and metalloproteinase with thrombospondin motifs (ADAMTSs) were upregulated. According to the results of differentially expressed genes (DEGs) and qRT-PCR, we evaluated the protein level of HOXD11 and found that the expression of HOXD11 was downregulated, reversed to MMPs and ADAMTSs but consistent with the cartilage-specific factors, SOX9 and COL2A1. In the lentivirus transfection experiments, HOXD11 overexpression reversed the effects in OA chondrocytes. In human OA articular cartilage, aberrant subchondral bone was formed in hematoxylin-eosin (H&E) and Safranin O and fast green (SOFG) staining results. Furthermore, according to immunohistochemistry findings, SOX9 and HOXD11 expression was inhibited. The results of this study established that HOXD11 was downregulated in OA cartilage and that overexpression of HOXD11 could prevent cartilage degradation in OA.

Pyruvate kinase M2 regulates kidney fibrosis through pericyte glycolysis during the progression from acute kidney injury to chronic kidney disease

We aimed to investigate the role of renal pericyte pyruvate kinase M2 (PKM2) in the progression of acute kidney injury (AKI) to chronic kidney disease (CKD). The role of PKM2 in renal pericyte-myofibroblast transdifferentiation was investigated in an AKI-CKD mouse model. Platelet growth factor receptor beta (PDGFRβ)-iCreERT2; tdTomato mice were used for renal pericyte tracing. Western blotting and immunofluorescence staining were used to examine protein expression. An 5-ethynyl-2'-deoxyuridine assay was used to measure renal pericyte proliferation. A scratch cell migration assay was used to analyse cell migration. Seahorse experiments were used to examine glycolytic rates. Enzyme-linked immunoassay was used to measure pyruvate kinase enzymatic activity and lactate concentrations. The PKM2 nuclear translocation inhibitors Shikonin and TEPP-46 were used to alter pericyte transdifferentiation. In AKI-CKD, renal pericytes proliferated and transdifferentiated into myofibroblasts and PKM2 is highly expressed in renal pericytes. Shikonin and TEPP-46 inhibited pericyte proliferation, migration, and pericyte-myofibroblast transdifferentiation by reducing nuclear PKM2 entry. In the nucleus, PKM2 promoted downstream lactate dehydrogenase A (LDHA) and glucose transporter 1 (GLUT1) transcription, which are critical for glycolysis. Therefore, PKM2 regulates pericyte glycolytic and lactate production, which regulates renal pericyte-myofibroblast transdifferentiation. PKM2-regulated renal pericyte-myofibroblast transdifferentiation by regulating downstream LDHA and GLUT1 transcription and lactate production. Reducing nuclear PKM2 import can reduce renal pericytes-myofibroblasts transdifferentiation, providing new ideas for AKI-CKD treatment.

Integrin β1-rich extracellular vesicles of kidney recruit Fn1+ macrophages to aggravate ischemia-reperfusion-induced inflammation

Ischemia-reperfusion injury-induced (IRI-induced) acute kidney injury is accompanied by mononuclear phagocyte (MP) invasion and inflammation. However, systematic analysis of extracellular vesicle-carried (EV-carried) proteins mediating intercellular crosstalk in the IRI microenvironment is still lacking. Multiomics analysis combining single-cell RNA-Seq data of kidney and protein profiling of kidney-EV was used to elucidate the intercellular communication between proximal tubular cells (PTs) and MP. Targeted adhesion and migration of various MPs were caused by the secretion of multiple chemokines as well as integrin β1-rich EV by ischemic-damaged PTs after IRI. These recruited MPs, especially Fn1+ macrophagocyte, amplified the surviving PT's inflammatory response by secreting the inflammatory factors TNF-α, MCP-1, and thrombospondin 1 (THBS-1), which could interact with integrin β1 to promote more MP adhesion and interact with surviving PT to further promote the secretion of IL-1β. However, GW4869 reduced MP infiltration and maintained a moderate inflammatory level likely by blocking EV secretion. Our findings establish the molecular bases by which chemokines and kidney-EV mediate PT-MP crosstalk in early IRI and provide insights into systematic intercellular communication.

Knowledge mapping of UMOD of English published work from 1985 to 2022: a bibliometric analysis

BACKGROUND

UMOD is exclusively produced by renal epithelial cells. Recent genome-wide association studies (GWAS) suggested that common variants in UMOD gene are closely connected with the risk of CKD. However, a comprehensive and objective report on the current status of UMOD research is lacking. Therefore, we aim to conduct a bibliometric analysis to quantify and identify the status quo and trending issues of UMOD research in the past.

METHODS

We collected data from the Web of Science Core Collection database and used the Online Analysis Platform of Literature Metrology, the Online Analysis Platform of Literature Metrology and Microsoft Excel 2019 to perform bibliometricanalysis and visualization.

RESULTS

Based on the data from the WoSCC database from 1985 to 2022, a total of 353 UMOD articles were published in 193 academic journals by 2346 authors from 50 different countries/regions and 396 institutions. The United States published the most papers. Professor Devuyst O from University of Zurich not only published the greatest number of UMOD-related papers but also is among the top 10 co-cited authors. KIDNEY INTERNATIONAL published the most necroptosis studies, and it was also the most cited journal. High-frequency keywords mainly included 'chronic kidney disease', 'Tamm Horsfall protein' and 'mutation'.

CONCLUSIONS

The number of UMOD-related articles has steadily increased over the past decades Current UMOD studies focused on Biological relevance of the UMOD to kidney function and potential applications in the risk of CKD mechanisms, these might provide ideas for further research in the UMOD field.

Single-cell dissection of cellular and molecular features underlying mesenchymal stem cell therapy in ischemic acute kidney injury

Mesenchymal stem cells (MSCs) exert beneficial therapeutic effects in acute kidney injury (AKI), while the detailed repair mechanism remains unclear. Herein, we probed the underlying mechanisms of MSC therapy in AKI by performing unbiased single-cell RNA sequencing in IRI model with/without MSC treatment. Our analyses uncovered the tubular epithelial cells (TECs) and immune cells transcriptomic diversity and highlighted a repair trajectory involving renal stem/progenitor cell differentiation. Our findings also suggested that profibrotic TECs expressing pro-fibrotic factors such as Zeb2 and Pdgfb promoted the recruitment of inflammatory monocytes and Th17 cells to injured kidney tissue, inducing TGF-β1 secretion and renal fibrosis. Finally, in addition to activating the repair properties of renal progenitor/stem cells, we uncovered a role for MSC-derived miR-26a-5p in mediating the therapeutic effects of MSCs by inhibiting Zeb2 expression and suppressing pro-fibrotic TECs and its subsequent recruitment of immune cell subpopulations. These findings may help to optimize future AKI treatment strategies.

The therapeutic effect of Shenhua tablet against mesangial cell proliferation and renal inflammation in mesangial proliferative glomerulonephritis

Shenhua tablet (SH), a formulation of traditional Chinese medicine, exerts renoprotective effect on chronic kidney diseases, and it has been found to restrain inflammation, but the mechanism is still unclear. Here, we explored the potential renoprotection of SH in mesangial proliferative glomerulonephritis (MsPGN) rat model induced by anti-Thy1 antibody. Administration of SH reduced urinary albumin/creatinine ratio (UACR) and significantly attenuated mesangial cell proliferation and renal inflammation. Notably, SH protected rats against renal inflammation, which was associated with decreasing macrophage infiltration and promoting macrophage anti-inflammatory activity. Network analysis combined with arrays identified the Janus kinase signal transducer and activator of transcription (JAK-STAT) signaling pathway as the main pathways of SH could target inflammation. Furthermore, it was confirmed that mesangial cell proliferation, which response to inflammation, were alleviated by ASS1 expression enhanced after SH administration both in vivo and in vitro. Collectively, SH has the beneficial on relieving the progression of MsPGN to alleviate inflammation and mesangial proliferation by inhibiting STAT3 phosphorylation and maintains the expression level of ASS1, might be an effective strategy for treating MsPGN.

Targeted VEGFA therapy in regulating early acute kidney injury and late fibrosis

Damage to peritubular capillaries is a key process that contributes to acute kidney injury (AKI) progression. Vascular endothelial growth factor A (VEGFA) plays a critical role in maintaining the renal microvasculature. However, the physiological role of VEGFA in various AKI durations remains unclear. A severe unilateral ischemia‒reperfusion injury model was established to provide an overview of VEGFA expression and the peritubular microvascular density from acute to chronic injury in mouse kidneys. Therapeutic strategies involving early VEGFA supplementation protecting against acute injury and late anti-VEGFA treatment for fibrosis alleviation were analyzed. A proteomic analysis was conducted to determine the potential mechanism of renal fibrosis alleviation by anti-VEGFA. The results showed that two peaks of extraglomerular VEGFA expression were observed during AKI progression: one occurred at the early phase of AKI, and the other occurred during the transition to chronic kidney disease (CKD). Capillary rarefaction progressed despite the high expression of VEGFA at the CKD stage, and VEGFA was associated with interstitial fibrosis. Early VEGFA supplementation protected against renal injury by preserving microvessel structures and counteracting secondary tubular hypoxic insults, whereas late anti-VEGFA treatment attenuated renal fibrosis progression. The proteomic analysis highlighted an array of biological processes related to fibrosis alleviation by anti-VEGFA, which included regulation of supramolecular fiber organization, cell-matrix adhesion, fibroblast migration, and vasculogenesis. These findings establish the landscape of VEGFA expression and its dual roles during AKI progression, which provides the possibility for the orderly regulation of VEGFA to alleviate early acute injury and late fibrosis.

The role of cellular crosstalk in the progression of diabetic nephropathy

Diabetic nephropathy (DN) is one of the most common complications of diabetes, and its main manifestations are progressive proteinuria and abnormal renal function, which eventually develops end stage renal disease (ESRD). The pathogenesis of DN is complex and involves many signaling pathways and molecules, including metabolic disorders, genetic factors, oxidative stress, inflammation, and microcirculatory abnormalities strategies. With the development of medical experimental techniques, such as single-cell transcriptome sequencing and single-cell proteomics, the pathological alterations caused by kidney cell interactions have attracted more and more attention. Here, we reviewed the characteristics and related mechanisms of crosstalk among kidney cells podocytes, endothelial cells, mesangial cells, pericytes, and immune cells during the development and progression of DN and highlighted its potential therapeutic effects.

A Simple Nomogram for Predicting Hospital Mortality of Patients Over 80 Years in ICU: An International Multicenter Retrospective Study

OBJECTIVES

This study aimed to develop and validate an easy-to-use intensive care unit (ICU) illness scoring system to evaluate the in-hospital mortality for very old patients (VOPs, over 80 years old).

METHODS

We performed a multicenter retrospective study based on the electronic ICU (eICU) Collaborative Research Database (eICU-CRD), Medical Information Mart for Intensive Care Database (MIMIC-III CareVue and MIMIC-IV), and the Amsterdam University Medical Centers Database (AmsterdamUMCdb). Least Absolute Shrinkage and Selection Operator regression was applied to variables selection. The logistic regression algorithm was used to develop the risk score and a nomogram was further generated to explain the score.

RESULTS

We analyzed 23 704 VOPs, including 3 726 deaths (10 183 [13.5% mortality] from eICU-CRD [development set], 12 703 [17.2%] from the MIMIC, and 818 [20.8%] from the AmsterdamUMC [external validation sets]). Thirty-four variables were extracted on the first day of ICU admission, and 10 variables were finally chosen including Glasgow Coma Scale, shock index, respiratory rate, partial pressure of carbon dioxide, lactate, mechanical ventilation (yes vs no), oxygen saturation, Charlson Comorbidity Index, blood urea nitrogen, and urine output. The nomogram was developed based on the 10 variables (area under the receiver operating characteristic curve: training of 0.792, testing of 0.788, MIMIC of 0.764, and AmsterdamUMC of 0.808 [external validating]), which consistently outperformed the Sequential Organ Failure Assessment, acute physiology score III, and simplified acute physiology score II.

CONCLUSIONS

We developed and externally validated a nomogram for predicting mortality in VOPs based on 10 commonly measured variables on the first day of ICU admission. It could be a useful tool for clinicians to identify potentially high risks of VOPs.

Regulation of pericyte metabolic reprogramming restricts the AKI to CKD transition

BACKGROUND AND AIMS

Acute kidney injury (AKI) is associated with high morbidity and mortality and is recognized as a long-term risk factor for progression to chronic kidney disease (CKD). The AKI to CKD transition is characterized by interstitial fibrosis and the proliferation of collagen-secreting myofibroblasts. Pericytes are the major source of myofibroblasts in kidney fibrosis. However, the underlying mechanism of pericyte-myofibroblast transition (PMT) is still unclear. Here we investigated the role of metabolic reprogramming in PMT.

METHODS

Unilateral ischemia/reperfusion-induced AKI to CKD mouse model and TGF-β-treated pericyte-like cells were used to detect the levels of fatty acid oxidation (FAO) and glycolysis, and the critical signaling pathways during PMT under the treatment of drugs regulating metabolic reprogramming.

RESULTS

PMT is characterized by a decrease in FAO and an increase in glycolysis. Enhancement of FAO by the peroxisome proliferator-activated receptor gamma coactivator-1α (PGC1α) activator ZLN-005 or suppression of glycolysis by the hexokinase 2 (HK2) inhibitor 2-DG can inhibit PMT, preventing the transition of AKI to CKD. Mechanistically, AMPK modulates various pathways involved in the metabolic switch from glycolysis to FAO. Specifically, the PGC1α-CPT1A pathway activates FAO, while inhibition of the HIF1α-HK2 pathway drives glycolysis inhibition. The modulations of these pathways by AMPK contribute to inhibiting PMT.

CONCLUSIONS

Metabolic reprogramming controls the fate of pericyte transdifferentiation and targets the abnormal metabolism of pericytes can effectively prevent AKI to CKD transition.

The PI3K-Akt-mTOR pathway mediates renal pericyte-myofibroblast transition by enhancing glycolysis through HKII

BACKGROUND

Pericyte-myofibroblast transition (PMT) has been confirmed to contribute to renal fibrosis in several kidney diseases, and transforming growth factor-β1 (TGF-β1) is a well-known cytokine that drives PMT. However, the underlying mechanism has not been fully established, and little is known about the associated metabolic changes.

METHODS

Bioinformatics analysis was used to identify transcriptomic changes during PMT. PDGFRβ + pericytes were isolated using MACS, and an in vitro model of PMT was induced by 5 ng/ml TGF-β1. Metabolites were analyzed by ultraperformance liquid chromatography (UPLC) and tandem mass spectrometry (MS). 2-Deoxyglucose (2-DG) was used to inhibit glycolysis via its actions on hexokinase (HK). The hexokinase II (HKII) plasmid was transfected into pericytes for HKII overexpression. LY294002 or rapamycin was used to inhibit the PI3K-Akt-mTOR pathway for mechanistic exploration.

RESULTS

An increase in carbon metabolism during PMT was detected through bioinformatics and metabolomics analysis. We first detected increased levels of glycolysis and HKII expression in pericytes after stimulation with TGF-β1 for 48 h, accompanied by increased expression of α-SMA, vimentin and desmin. Transdifferentiation was blunted when pericytes were pretreated with 2-DG, an inhibitor of glycolysis. The phosphorylation levels of PI3K, Akt and mTOR were elevated during PMT, and after inhibition of the PI3K-Akt-mTOR pathway with LY294002 or rapamycin, glycolysis in the TGF-β1-treated pericytes was decreased. Moreover, PMT and HKII transcription and activity were blunted, but the plasmid-mediated overexpression of HKII rescued PMT inhibition.

CONCLUSIONS

The expression and activity of HKII as well as the level of glycolysis were increased during PMT. Moreover, the PI3K-Akt-mTOR pathway regulates PMT by increasing glycolysis through HKII regulation.

Fufang Shenhua tablet inhibits renal fibrosis by inhibiting PI3K/AKT

BACKGROUND

Fufang Shenhua tablet (SHT), a traditional Chinese medicine compound, has been utilized in the clinical management of chronic kidney disease (CKD) for a long time. Nevertheless, the fundamental active constituents and potential mechanism of action remain unclear. Thus, the objective of this study was to investigate the renoprotective effect of SHT on residual renal tissue in CKD model rats and to explore its primary efficacious components and their underlying mechanism.

METHODS

After a 12-week period of SHT treatment through gavage in a 5/6 nephrectomized animal model of CKD, we evaluated the body weight, renal function, and renal pathological changes. Furthermore, the expression levels of fibronectin (FN), collagen I (COL-1), α-smooth muscle actin (α-SMA), and vimentin in renal tissues were assessed. In addition, network pharmacology analysis and molecular docking were utilized to predict the primary active components, potential therapeutic targets, and intervention pathways through which SHT could potentially exert its anti-kidney fibrosis effects. Subsequently, these predictions were validated in renal tissues of rats with CKD and in transforming growth factor β1 (TGF-β1)-induced HK-2 cells.

RESULTS

SHT significantly improved renal function and reduced renal pathological damage and fibrosis in CKD model rats. Network pharmacological analysis identified 62 active components in SHT, with quercetin ranked first, and 105 protein targets shared by SHT and CKD. Based on the protein‒protein interaction network (PPI) and the SHT-CKD-pathway network, AKT1, MYC, IL2, and VEGFA were identified as key targets. Furthermore, GO and KEGG pathway enrichment analyses indicated that the renoprotective effect of SHT on CKD was closely associated with the PI3K/AKT signaling pathway. Molecular docking results demonstrated that the main active components of SHT had a strong binding affinity to the hub genes. During experimental validation, SHT hindered the activity of the PI3K/AKT signaling pathway in the renal tissue of CKD model rats. Furthermore, activation of the PI3K/AKT signaling pathway was correlated with a modified fibrotic phenotype in rats with 5/6 nephrectomy-induced CKD and TGF-β1-induced HK-2 cells. Conversely, SHT and quercetin curtailed the activation of the PI3K/AKT signaling pathway and inhibited the formation of renal fibrosis, thus indicating that the PI3K/AKT signaling pathway is the basis of the antifibrotic effects of SHT. Ultimately, administration of the PI3K/AKT agonist 740Y-P counteracted the fibrotic phenotype of TGF-β1-induced HK-2 cells induced by SHT.

CONCLUSIONS

In this investigation, we employed a fusion of systems pharmacology and in vivo and in vitro experiments to elucidate the mechanism of SHT's antifibrotic properties via obstruction of the PI3K/AKT signaling pathway. Additionally, we surmised that AKT may be the principal target of SHT for the management of CKD and that quercetin may be its efficacious component. We have thus identified SHT as a promising drug for the amelioration of renal fibrosis and the progression of CKD.

Optimization strategies of mesenchymal stem cell-based therapy for acute kidney injury

Considering the high prevalence and the lack of targeted pharmacological management of acute kidney injury (AKI), the search for new therapeutic approaches for it is in urgent demand. Mesenchymal stem cells (MSCs) have been increasingly recognized as a promising candidate for the treatment of AKI. However, clinical translation of MSCs-based therapies is hindered due to the poor retention and survival rates as well as the impaired paracrine ability of MSCs post-delivery. To address these issues, a series of strategies including local administration, three-dimensional culture, and preconditioning have been applied. Owing to the emergence and development of these novel biotechnologies, the effectiveness of MSCs in experimental AKI models is greatly improved. Here, we summarize the different approaches suggested to optimize the efficacy of MSCs therapy, aiming at promoting the therapeutic effects of MSCs on AKI patients.

Fufang shenhua tablet, astragali radix and its active component astragaloside IV: Research progress on anti-inflammatory and immunomodulatory mechanisms in the kidney

Background: Given the limited treatment options available for kidney disease, a significant number of patients turn to alternative therapies, including traditional Chinese medicine. Among these therapies, the Fufang Shenhua tablet (SHT) has garnered attention for its effectiveness in addressing the most common deficiency of Qi and Yin in chronic glomerulonephritis. Notably, the sovereign drug of SHT is Astragali Radix (AR), with the most abundant and effective component being Astragaloside IV (AS-IV). AS-IV has been shown to possess anti-inflammatory and immunomodulatory properties, and it is extensively used in treating kidney diseases. Nevertheless, the molecular mechanisms underlying its action are numerous and intricate, and a comprehensive understanding is yet to be achieved.

Aim of the review: Thus, we have thoroughly examined the existing research and outlined the advancements made in investigating the anti-inflammatory and immunomodulatory mechanisms of SHT, AR and its active component AS-IV, in relation to kidney health. This serves as a dependable foundation for conducting more comprehensive investigations, evaluating efficacy, and making further improvements in the future.

Materials and methods: We conducted a comprehensive literature search utilizing multiple globally recognized databases, including Web of Science, Google Scholar, PubMed, ScienceDirect, Wiley, ACS, Springer, and CNKI. The search keywords used in this study were “Fufang Shenhua tablet,” “Astragali Radix,” “Astragaloside IV,” and “Anti-inflammatory” or “Immunity.”

Results: The mechanism of inflammation inhibition by SHT, AR and its active component AS-IV is mainly related to the signaling pathways such as NF-κB, TLRs, PI3K/AKT, Wnt/β-catenin, and JAK-STAT. Immunomodulation exerts not only activating, stimulating, and regulating effects on macrophages and dendritic cells, but also on immune organs, T-lymphocytes, B-lymphocytes, and a myriad of cytokines. Moreover, the SHT, AR and its active component AS-IV also demonstrate regulatory effects on renal cells, including glomerular mesangial cells, tubular epithelial cells, and podocytes.

Conclusion: To summarize, SHT, AR and its active component AS-IV, exhibit notable therapeutic effects in kidney-related ailments, and their molecular mechanisms for anti-inflammatory and immunomodulatory effects have been extensively explored. However, further standard clinical trials are necessary to evaluate their safety and efficacy in the adjunctive treatment of kidney-related diseases. Moreover, in-depth studies of unverified chemical components and regulatory mechanisms in SHT are required. It is our belief that with continued research, SHT, AR and its active component AS-IV are poised to pave the way for enhancing therapeutic outcomes in kidney-related ailments.

Mesenchymal stem cells ameliorate cisplatin-induced acute kidney injury via let-7b-5p

Acute kidney injury (AKI) is a clinically common kidney disease. Age is an important factor that contributes to the susceptibility to AKI. Mesenchymal stem cells (MSCs) are a promising therapy for AKI, and miRNAs in exosomes (Exos) derived from MSCs are an important aspect of MSC treatment. However, the therapeutic effect of miRNA from MSC-derived Exos on AKI and the related mechanism have not been fully clarified. Whether there is a relationship between the mechanisms of senescence for AKI susceptibility and the therapeutic effect of MSCs has not been studied. We compared the degree of cisplatin-induced AKI injury in young and elderly mice and investigated changes in the expression of p53 and markers of DNA damage and apoptosis, which are important in both senescence and AKI. Ageing mice exhibited increased expression of p53 and pro-apoptosis markers. Upregulation of the senescence-associated DNA damage/p53 pathway may be an important susceptibility factor for cisplatin-induced AKI. Treatment with MSCs can reduce the degree of DNA damage and suppress p53 expression and apoptosis. Upon screening for differentially expressed miRNAs, let-7b-5p levels were found to be lower in aged mice than in young mice, and MSC treatment increased let-7b-5p levels. The presence of let-7b-5p in MSC-derived Exos alleviates tubular epithelial cell apoptosis by inhibiting p53, which reduces DNA damage and apoptosis pathway activity. Let-7b-5p downregulation may lead to increased renal AKI susceptibility, thus indicating that this miRNA is a potential driver of the MSC treatment response in AKI.

High-Resolution Femtosecond Laser-Induced Carbon and Ag Hybrid Structure for Bend Sensing

Miniaturized resistance-based portable bending sensors have been widely used for human health monitoring in recent years. Their sensitivities are defined by their resistance variations (ΔR/R), which strongly rely on the conductivity and minimum line width of the sensing unit. Laser-induced carbonization is a fast and simple method to fabricate porous-sensing structures. However, the fabrication resolution of conductive and deformation-sensitive structures is limited by the thermal effect of commonly used laser sources. With the assistance of femtosecond laser temporal shaping, plasma ejection confinement, and silver nitrate doping, the sheet resistance of the sensing structure was improved from 15 to 0.0004 Ω/□. A thin line with a lateral resolution of 6.5 μm is fabricated as the sensing unit. The fFabricated structures are characterized by electron microscopy, Raman spectroscopy, energy-dispersive spectroscopy, X-ray scattering, and time-resolved images. The strain sensor demonstrates a ΔR/R of 25.8% with a rising edge of 109 ms in the cyclic bending test. The sensor is further applied for detecting human pulse and finger bending.

Interaction of RARRES1 with ICAM1 modulates macrophages to suppress the progression of kidney renal clear cell carcinoma

Background

RARRES1 is a tumor suppressor protein, and its expression is suppressed in various tumor cells. However, whether it participates in the immune response in kidney renal clear cell carcinoma (KIRC) is unknown, and the defined mechanism is not clear. Therefore, the mechanism of RARRES1 in KIRC is worthy of investigation.

Methods

We analysed the expression and function of RARRES1 with The Cancer Genome Atlas (TCGA) database. The Kaplan–Meier curve was adopted to estimate survival. RARRES1-correlated genes were obtained from the UALCAN database and subjected to Gene Ontology (GO) enrichment and protein–protein interaction (PPI) network analyses. The correlation analysis between tumor-infiltrating immune cells and selected genes were performed with TIMER database. We also investigated the possible function of RARRES1 in KIRC by coculturing Caki-1 cells with THP-1 cells. Immunofluorescence assay was performed to study the RARRES1 expression in difference grade KIRC tissues.

Results

The expression of RARRES1 was negatively correlated with survival in KIRC patients. The GO biological process term most significantly enriched with the RARRES1-correlated genes was regulation of cell adhesion. ICAM1, which exhibited a relatively highest correlation with RARRES1, is positively correlated with the infiltration level of macrophages. RARRES1 could enhance the expression of ICAM1 in Caki-1 cells and then induce the activation of M1 THP-1 cells to decrease the viability and induce the apoptosis of Caki-1 cells.

Conclusion

RARRES1 plays an antitumor role by promoting ICAM1 expression and inducing the activation of M1 macrophages. We offer insights into the molecular mechanism of KIRC and reveal a potential therapeutic target.

Artificial Kidney Capsule Packed with Mesenchymal Stem Cell-Laden Hydrogel for the Treatment of Rhabdomyolysis-Induced Acute Kidney Injury

Acute kidney injury (AKI) has emerged as a major public health problem affecting millions of people worldwide without specific and satisfactory therapies due to the lack of an effective delivery approach. In the past few decades, hydrogels present infinite potential in localized drug delivery, while their poor adhesion to moist tissue and isotropic diffusion character always restrict the therapeutic efficiency and may lead to unwanted side effects. Herein, we proposed a novel therapeutic strategy for AKI via a customizable artificial kidney capsule (AKC) together with a mesenchymal stem cell (MSC)-laden hydrogel. Specifically, an elastic capsule owning an inner chamber with the same size and shape as the kidney is designed and fabricated through three-dimensional (3D) modeling and printing, serving as an outer wrap for kidney and cell-laden hydrogels. According to the in vitro experiment, the excellent biocompatibility of gelatin-based hydrogel ensures viability and proliferation of MSCs. In vivo mice experiments proved that this concept of AKC-assisted kidney drug delivery could efficiently reduce epithelial cell apoptosis and minimize the damage of the renal tubular structure for mice suffering AKI. Such a strategy not only provides a promising alternative in the treatment of AKI but also offers a feasible and versatile approach for the repair and recovery of other organs.

Prediction of 3-year risk of diabetic kidney disease using machine learning based on electronic medical records

BACKGROUND

Established prediction models of Diabetic kidney disease (DKD) are limited to the analysis of clinical research data or general population data and do not consider hospital visits. Construct a 3-year diabetic kidney disease risk prediction model in patients with type 2 diabetes mellitus (T2DM) using machine learning, based on electronic medical records (EMR).

METHODS

Data from 816 patients (585 males) with T2DM and 3 years of follow-up at the PLA General Hospital. 46 medical characteristics that are readily available from EMR were used to develop prediction models based on seven machine learning algorithms (light gradient boosting machine [LightGBM], eXtreme gradient boosting, adaptive boosting, artificial neural network, decision tree, support vector machine, logistic regression). Model performance was evaluated using the area under the receiver operating characteristic curve (AUC). Shapley additive explanation (SHAP) was used to interpret the results of the best performing model.

RESULTS

The LightGBM model had the highest AUC (0.815, 95% CI 0.747-0.882). Recursive feature elimination with random forest and SHAP plot based on LightGBM showed that older patients with T2DM with high homocysteine (Hcy), poor glycemic control, low serum albumin (ALB), low estimated glomerular filtration rate (eGFR), and high bicarbonate had an increased risk of developing DKD over the next 3 years.

CONCLUSIONS

This study constructed a 3-year DKD risk prediction model in patients with T2DM and normo-albuminuria using machine learning and EMR. The LightGBM model is a tool with potential to facilitate population management strategies for T2DM care in the EMR era.

Efficacy and Safety of Daprodustat Vs rhEPO for Anemia in Patients With Chronic Kidney Disease: A Meta-Analysis and Trial Sequential Analysis

Introduction: Daprodustat, a novel hypoxia-inducible factor prolyl-hydroxylase inhibitor (HIF-PHI), its efficacy and safety remain unclear. Thus, we conducted this meta-analysis aiming at investigating its efficacy and safety on the treatment of patients with chronic kidney disease (CKD)-related anemia.

Methods: We systematically searched for relevant studies in PubMed, Embase, Cochrane Library and Clinical Trial Registries databases from inception until December 2021. We selected randomized controlled trials comparing daprodustat with recombinant human erythropoietin (rhEPO) in anemia patients with CKD with or without dialysis.

Results: Seven studies including 7933 patients met the inclusion criteria. For both nondialysis-dependent (NDD-) CKD and dialysis-dependent (DD-) CKD patients, the pooled results showed that there was no significant difference in the changes in hemoglobin levels between the daprodustat and rhEPO groups (mean difference (MD) = −0.01, 95% confidence interval (CI) = −0.38, 0.35, p = 0.95; MD = 0.15, 95% CI = −0.29, 0.60, p = 0.50; respectively). In addition, a significant increase in transferrin saturation (TSAT), total iron binding capacity (TIBC) and total iron was observed in daprodustat groups compared with rhEPO groups in DD-CKD patients (p < 0.05). As for safety, the overall frequency of adverse events was similar between the daprodustat and rhEPO groups in DD-CKD patients (relative risk (RR) = 0.99, 95%CI = 0.92, 1.06, p = 0.76), and the trial sequential analysis (TSA) confirmed this result. But for NDD-CKD patients, the incidence of adverse events in the daprodustat groups was significantly higher than that of rhEPO groups (RR = 1.04, 95%CI = 1.01,1.07, p = 0.02), while the TSA corrected this result. No trend of increasing incidence of serious adverse events was found in all daprodustat treated patients, but the TSA could not confirm this result.

Conclusion: Although daprodustat was noninferior to rhEPO in correcting anemia in both NDD-CKD and DD-CKD patients, it seemed to have a better effect on optimizing iron metabolism in DD-CKD patients. Daprodustat may be a promising alternative for the treatment of anemia in patients with CKD. However, due to the lack of included studies, future researches are needed to further evaluate the therapeutic effect of daprodustat.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/, identifier CRD42021229636.

Modulation of transforming growth factor-β-induced kidney fibrosis by leucine-rich ⍺-2 glycoprotein-1

Kidney fibrosis is considered the final convergent pathway for progressive chronic kidney diseases, but there is still a paucity of success in clinical application for effective therapy. We recently demonstrated that the expression of secreted leucine-rich α-2 glycoprotein-1 (LRG1) is associated with worsened kidney outcomes in patients with type 2 diabetes and that LRG1 enhances endothelial transforming growth factor-β signaling to promote diabetic kidney disease progression. While the increased expression of LRG1 was most prominent in the glomerular endothelial cells in diabetic kidneys, its increase was also observed in the tubulointerstitial compartment. Here, we explored the potential role of LRG1 in kidney epithelial cells and TGF-β-mediated tubulointerstitial fibrosis independent of diabetes. LRG1 expression was induced by tumor necrosis factor-α in cultured kidney epithelial cells and potentiated TGF-β/Smad3 signal transduction. Global Lrg1 loss in mice led to marked attenuation of tubulointerstitial fibrosis in models of unilateral ureteral obstruction and aristolochic acid fibrosis associated with concomitant decreases in Smad3 phosphorylation in tubule epithelial cells. In mice with kidney epithelial cell-specific LRG1 overexpression, while no significant phenotypes were observed at baseline, marked exacerbation of tubulointerstitial fibrosis was observed in the obstructed kidneys. This was associated with enhanced Smad3 phosphorylation in both kidney epithelial cells and α-smooth muscle actin-positive interstitial cells. Co-culture of kidney epithelial cells with primary kidney fibroblasts confirmed the potentiation of TGF-β-mediated Smad3 activation in kidney fibroblasts through epithelial-derived LRG1. Thus, our results indicate that enhanced LRG1 expression-induced epithelial injury is an amplifier of TGF-β signaling in autocrine and paracrine manners promoting tubulointerstitial fibrosis. Hence, therapeutic targeting of LRG1 may be an effective means to curtail kidney fibrosis progression in chronic kidney disease.

Ginsenoside Rb1 alleviates diabetic kidney podocyte injury by inhibiting aldose reductase activity

Panax notoginseng, a traditional Chinese medicine, exerts beneficial effect on diabetic kidney disease (DKD), but its mechanism is not well clarified. In this study we investigated the effects of ginsenoside Rb1 (Rb1), the main active ingredients of Panax notoginseng, in alleviating podocyte injury in diabetic nephropathy and the underlying mechanisms. In cultured mouse podocyte cells, Rb1 (10 μM) significantly inhibited high glucose-induced cell apoptosis and mitochondrial injury. Furthermore, Rb1 treatment reversed high glucose-induced increases in Cyto c, Caspase 9 and mitochondrial regulatory protein NOX4, but did not affect the upregulated expression of aldose reductase (AR). Molecular docking analysis revealed that Rb1 could combine with AR and inhibited its activity. We compared the effects of Rb1 with eparestat, a known aldose reductase inhibitor, in high glucose-treated podocytes, and found that both alleviated high glucose-induced cell apoptosis and mitochondrial damage, and Rb1 was more effective in inhibiting apoptosis. In AR-overexpressing podocytes, Rb1 (10 μM) inhibited AR-mediated ROS overproduction and protected against high glucose-induced mitochondrial injury. In streptozotocin-induced DKD mice, administration of Rb1 (40 mg·kg^-1·d^-1, ig, for 7 weeks) significantly mitigated diabetic-induced glomerular injuries, such as glomerular hypertrophy and mesangial matrix expansion, and reduced the expression of apoptotic proteins. Collectively, Rb1 combines with AR to alleviate high glucose-induced podocyte apoptosis and mitochondrial damage, and effectively mitigates the progression of diabetic kidney disease.

Cxcl10 deficiency attenuates renal interstitial fibrosis through regulating epithelial-to-mesenchymal transition

IFN-γ-inducible protein 10 (IP-10, CXCL10) has been widely demonstrated to be involved in multiple kidney pathological processes. However, the role of CXCL10 in renal fibrosis remains unclear. In this study, Cxcl10-deficient (Cxcl10-/-) mice were used to generate the unilateral ureteral obstruction (UUO) model. The level of renal fibrosis and inflammatory cell infiltration was examined in vivo and the effects of CXCL10 on EMT process of HK-2 cells was investigated in vitro. We observed that the injury degree of renal tissue and the collagen deposition levels were lighter and the expression of α-SMA, collagen I and fibronectin was significantly reduced in Cxcl10-/- mice, while the expression of E-cadherin was increased. However, interstitial F4/80-positive macrophages and CD4-positive T lymphocytes were unaffected by knockout of Cxcl10. Furthermore, IFN-γ or CXCL10 stimulation could obviously promote the expression of α-SMA, collagen I, fibronectin and reduce the expression of E-cadherin in HK-2 cells, which could be inhibited by transfection of Cxcl10-siRNA. Our findings suggested Cxcl10 knockout could reduce renal dysfunction and inhibit renal fibrosis through regulating EMT process of renal tubular epithelial cells in murine UUO model. These results may provide a novel insight into the mechanism and a potential therapy target of renal fibrosis.

One-Step In Situ Patternable Reduction of a Ag-rGO Hybrid Using Temporally Shaped Femtosecond Pulses

In recent years, metallic nanoparticle (NP)–two-dimensional material hybrids have been widely used for photocatalysis and photoreduction. Here, we introduce a femtosecond laser reduction approach that relies on the repetitive ablation of recast layers by usi–ng temporally shaped pulses to achieve the fast fabrication of metallic NP–two-dimensional material hybrids. We selectively deposited silver-reduced graphene oxide (Ag–rGO) hybrids on different substrates under various fabrication conditions. The deposition of the hybrids was attributed to the redistribution of the cooling ejected plume after multiple radiation pulses and the exchange of carriers with ejected plume ions containing activated species such as small carbon clusters and H₂O. The proposed one-step in situ fabrication method is a competitive fabrication process that eliminates the additive separation process and exhibits morphological controllability. The Ag–rGO hybrids demonstrate considerable potential for chemomolecular and biomolecular detection because the surface-enhanced Raman scattering signal of the enhancement factor reached 4.04 × 10⁸.

Insulin-Like Growth Factor Binding Proteins in Kidney Disease

The seven members of the insulin-like growth factor (IGF) binding protein family (IGFBPs) were initially considered to be the regulatory proteins of IGFs in the blood circulation, mainly as the subsequent reserve for bidirectional regulation of IGF function during environmental changes. However, in recent years, IGFBPs has been found to have many functions independent of IGFs. The role of IGFBPs in regulating transcription, inducing cell migration and apoptosis is closely related to the occurrence and development of kidney disease. IGFBP-1, IGFBP-3, IGFBP-4 are closely associated with diabetes and diabetic nephropathy. IGFBP-3, IGFBP-4, IGFBP-5, IGFBP-6 are involved in different kidney disease such as diabetes, FSGS and CKD physiological process as apoptosis proteins, IGFBP-7 has been used in clinical practice as a biomarker for early diagnosis and prognosis of AKI. This review focuses on the differential expression and pathogenesis of IGFBPs in kidney disease.

Primary cilium in kidney development, function and disease

The primary cilium is a hair-like, microtubule-based organelle that is covered by the cell membrane and extends from the surface of most vertebrate cells. It detects and translates extracellular signals to direct various cellular signaling pathways to maintain homeostasis. It is mainly distributed in the proximal and distal tubules and collecting ducts in the kidney. Specific signaling transduction proteins localize to primary cilia. Defects in cilia structure and function lead to a class of diseases termed ciliopathies. The proper functioning of primary cilia is essential to kidney organogenesis and the maintenance of epithelial cell differentiation and proliferation. Persistent cilia dysfunction has a role in the early stages and progression of renal diseases, such as cystogenesis and acute tubular necrosis (ATN). In this review, we focus on the central role of cilia in kidney development and illustrate how defects in cilia are associated with renal disease progression.

Renal primary cilia lengthen in the progression of diabetic kidney disease

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease, and its early pathogenesis is critical. Shear stress caused by glomerular hyperfiltration contributes to the initiation of kidney injury in diabetes. The primary cilium of renal tubular epithelial cells (RTECs) is an important mechanical force sensor of shear stress and regulates energy metabolism homeostasis in RTECs to ensure energy supply for reabsorption functions, but little is known about the alterations in the renal cilium number and length during the progression of DKD. Here, we demonstrate that aberrant ciliogenesis and dramatic increase in the cilium length, the number of ciliated cells, and the length of cilia are positively correlated with the DKD class in the kidney biopsies of DKD patients by super-resolution imaging and appropriate statical analysis methods. This finding was further confirmed in STZ-induced or db/db diabetic mice. These results suggest that the number and length of renal cilia may be clinically relevant indicators and that cilia will be attractive therapeutic targets for DKD.

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Objective: To examine the safety and feasibility of uniportal video-assisted thoracoscopic (VATS) decortication in patients presenting with stage Ⅲ tuberculous empyema. Methods: From August 2017 to July 2020, 158 patients of stage Ⅲ tuberculous empyema underwent uniportal VATS decortication with partial rib resection and customized periosteal stripper in Department of Thoracic Surgery, Shanghai Pulmonary Hospital. There were 127 males and 31 females, aged (M(IQR)) 32(28) years (range:14 to 78 years). Follow-up was performed in the outpatient clinic or via social communication applications, at monthly thereafter. If there was no air leak and chest tube drainage was less than 50 ml/day, a chest CT was performed. If the lung was fully re-expanded, chest tubes were removed. All patients received a follow-up chest CT 3 to 6 months following their initial operations which was compared to their preoperative imaging. Results: There was one conversion to open thoracotomy. The operative time was 2.75 (2.50) hours (range: 1.5 to 7.0 hours), and median blood loss was 100 (500) ml (range: 50 to 2 000 ml). There were no perioperative mortalities. There were no major complications except 1 case of redo-VATS for hemostasis due to excessive drainage and 1 case of incision infection, The incidence of prolonged air leaks (>5 days) was 80.3%(126/157). The postoperative hospital stay was 5.00 (2.25) days (range:2 to 15 days). All patients were discharged with 2 chest tubes, and the median duration drainage was 21.00 (22.50) days (range: 3 to 77 days). Follow-up was completed in all patients over a duration of 20 (14) months (range: 12 to 44 months). At follow-up, 149 patients(94.9%) recovered to grade Ⅰ level, 7 patients to grade Ⅱ level, and 1 patient to grade Ⅲ level. Conclusion: Uniportal VATS decortication involving partial rib resection and a customized periosteal stripper is safe and effective for patients with stage Ⅲ tuberculous empyema.

Safety and Efficacy of Roxadustat for Anemia in Patients With Chronic Kidney Disease: A Meta-Analysis and Trial Sequential Analysis

Background: Roxadustat, a hypoxia-inducible factor prolyl-hydroxylase inhibitor (HIF-PHI), has been used to treat anemia in patients with chronic kidney disease (CKD). However, its safety and efficacy remain controversial.

Methods: The PubMed, EMBASE, Science Citation Index, Cochrane Central Register of Controlled Trials, and Clinical Trial Registries databases were searched for relevant studies published up to April 2021. We identified randomized controlled trials (RCTs) comparing roxadustat with placebo or erythropoiesis-stimulating agents (ESAs) in anemia patients with CKD with or without dialysis.

Results: Eleven studies including 6,631 patients met the inclusion criteria. In non-dialysis-dependent (NDD-) and dialysis-dependent (DD-) CKD patients, the total adverse events were not significantly different between the roxadustat and control (placebo for NDD-CKD patients and ESA for DD-CKD patients) groups [relative risk (RR) = 1.02, 95% confidence interval (CI) = 1.00, 1.04, P = 0.08, and RR = 1.22, 95% CI = 0.91, 1.64, P = 0.18, respectively], and the trial sequential analysis (TSA) confirmed the result in the NDD-CKD groups. No significant differences in hyperkalemia and infection incidences were found between roxadustat and placebo in the DD-CKD groups. The pooled results showed that roxadustat significantly increased the hemoglobin response rate compared with placebo in the NDD-CKD group and had an effect similar to that of ESA in the DD-CKD group. However, iron metabolism parameters did not seem to be obviously optimized by roxadustat.

Conclusion: Roxadustat can be safely used in CKD patients. Oral roxadustat was more effective than placebo as a therapy for anemia in NDD-CKD patients and non-inferior to ESA in correcting anemia in DD-CKD patients. However, additional clinical trials are still needed to further prove whether roxadustat can optimize iron metabolism.

Interpretable Machine Learning Model for Early Prediction of Mortality in ICU Patients with Rhabdomyolysis

PURPOSE

Rhabdomyolysis (RM) is a complex set of clinical syndromes that involves the rapid dissolution of skeletal muscles. Mortality from RM is approximately 10%. This study aimed to develop an interpretable and generalizable model for early mortality prediction in RM patients.

METHOD

Retrospective analyses were performed on two electronic medical record databases: the eICU Collaborative Research Database and the Medical Information Mart for Intensive Care III database. We extracted data from the first 24 h after patient ICU admission. Data from the two data sets were merged for further analysis. The merged data sets were randomly divided, with 70% used for training and 30% for validation. We used the machine learning model extreme gradient boosting (XGBoost) with the Shapley additive explanation method to conduct early and interpretable predictions of patient mortality. Five typical evaluation indexes were adopted to develop a generalizable model.

RESULTS

In total, 938 patients with RM were eligible for this analysis. The area under the receiver operating characteristic curve (AUC) of the XGBoost model in predicting hospital mortality was 0.871, the sensitivity was 0.885, the specificity was 0.816, the accuracy was 0.915, and the F1 score was 0.624. The XGBoost model performance was superior to that of other models (logistic regression, AUC = 0.862; support vector machine, AUC = 0.843; random forest, AUC = 0.825; and naive Bayesian, AUC = 0.805) and clinical scores (Sequential Organ Failure Assessment, AUC = 0.747; Acute Physiology Score III, AUC = 0.721).

CONCLUSIONS

Although the XGBoost model is still not great from an absolute performance perspective, it provides better predictive performance than other models for estimating the mortality of patients with RM based on patient characteristics in the first 24 h of admission to the ICU.

Nanopatterning of silicon via the near-field enhancement effect upon double-pulse femtosecond laser exposure

Utilizing the near-field enhancement effect of a polystyrene microsphere, direct ablation of nanohole arrays by a temporal-shaping femtosecond (fs) laser pulse is presented. The nanohole arrays, which are circular, regular, and free of cracks, were processed without extra post-processing, and their average diameter decreased gradually, as the double-pulse delay increased until 2500 fs. The simulated results by a plasma model and finite difference time domain solution demonstrate that the size decrease of the structure is attributed to the increase of the ablation threshold of silicon. Through fs laser near-field fabrication, the FWHM of nanoholes can be reduced to approximately 50 nm (λ/16) and even to 23 nm when using the second harmonic laser at a wavelength of 400 nm.

Integrating Tumor Sequencing Into Clinical Practice for Patients With Mismatch Repair-Deficient Lynch Syndrome Spectrum Cancers

INTRODUCTION

Uninformative germline genetic testing presents a challenge to clinical management for patients suspected to have Lynch syndrome, a cancer predisposition syndrome caused by germline variants in the mismatch repair (MMR) genes or EPCAM.

METHODS

Among a consecutive series of MMR-deficient Lynch syndrome spectrum cancers identified through immunohistochemistry-based tumor screening, we investigated the clinical utility of tumor sequencing for the molecular diagnosis and management of suspected Lynch syndrome families. MLH1-deficient colorectal cancers were prescreened for BRAF V600E before referral for genetic counseling. Microsatellite instability, MLH1 promoter hypermethylation, and somatic and germline genetic variants in the MMR genes were assessed according to an established clinical protocol.

RESULTS

Eighty-four individuals with primarily colorectal (62%) and endometrial (31%) cancers received tumor-normal sequencing as part of routine clinical genetic assessment. Overall, 27% received a molecular diagnosis of Lynch syndrome. Most of the MLH1-deficient tumors were more likely of sporadic origin, mediated by MLH1 promoter hypermethylation in 54% and double somatic genetic alterations in MLH1 (17%). MSH2-deficient, MSH6-deficient, and/or PMS2-deficient tumors could be attributed to pathogenic germline variants in 37% and double somatic events in 28%. Notably, tumor sequencing could explain 49% of cases without causal germline variants, somatic MLH1 promoter hypermethylation, or somatic variants in BRAF.

DISCUSSION

Our findings support the integration of tumor sequencing into current Lynch syndrome screening programs to improve clinical management for individuals whose germline testing is uninformative.

Efficacy and safety of finerenone in patients with chronic kidney disease: a systematic review with meta-analysis and trial sequential analysis

BACKGROUND

The efficacy and safety of finerenone are unknown. Therefore, we performed this meta-analysis to investigate the efficacy and safety of finerenone in patients with chronic kidney disease (CKD).

METHODS

We systematically searched for relevant studies in the PubMed, Embase and Cochrane Library databases from database inception until December 2020. We selected randomized controlled trials assessing finerenone treatment in patients with CKD.

RESULTS

Four trials (n=7,048) met the inclusion criteria. Compared with placebo, finerenone significantly reduced the urine albumin-to-creatinine ratio (UACR) in patients with CKD {mean difference (MD), -0.30 [95% confidence interval (CI), -0.50, -0.11], P<0.05}, and trial sequential analysis (TSA) confirmed this result. No significant difference was observed in eGFR in patients with CKD between the finerenone and placebo groups [MD, -0.90 (95% CI, -3.84 to 2.04), P>0.05]. Overall, the frequency of adverse events was similar in the two groups [relative risk (RR), 1. 00 (95% CI, 0.98, 1.02), P>0.05], and TSA confirmed this result. However, the finerenone group exhibited a lower risk of cardiovascular disorders and a higher risk of hyperkalemia than the placebo group [RR, 0.92 (95% CI, 0.85, 0.99), P<0.05 and RR, 2.04 (95% CI, 1.77, 2.34), P<0.00001, respectively].

DISCUSSION

This meta-analysis indicated that finerenone confers an important antiproteinuric effect on patients with CKD and reduces the risk of cardiovascular disorders in these patients. Finerenone may be a promising therapy option for patients with CKD.

TRIAL REGISTRATION

PROSPERO registration number: CRD42021222404.

TROPHY-U-01: A Phase II Open-Label Study of Sacituzumab Govitecan in Patients With Metastatic Urothelial Carcinoma Progressing After Platinum-Based Chemotherapy and Checkpoint Inhibitors

PURPOSE

Patients with metastatic urothelial carcinoma (mUC) who progress on platinum-based combination chemotherapy (PLT) and checkpoint inhibitors (CPIs) have limited options that offer objective response rates (ORRs) of approximately 10% with a median overall survival (OS) of 7-8 months. Sacituzumab govitecan (SG) is a TROP-2-directed antibody-drug conjugate with an SN-38 payload that has shown preliminary activity in mUC.

METHODS

TROPHY-U-01 (ClinicalTrials.gov identifier: NCT03547973) is a multicohort, open-label, phase II, registrational study. Cohort 1 includes patients with locally advanced or unresectable or mUC who had progressed after prior PLT and CPI. Patients received SG 10 mg/kg on days 1 and 8 of 21-day cycles. The primary outcome was centrally reviewed ORR; secondary outcomes were progression-free survival, OS, duration of response, and safety.

RESULTS

Cohort 1 included 113 patients (78% men; median age, 66 years; 66.4% visceral metastases; median of three [range, 1-8] prior therapies). At a median follow-up of 9.1 months, the ORR was 27% (31 of 113; 95% CI, 19.5 to 36.6); 77% had decrease in measurable disease. Median duration of response was 7.2 months (95% CI, 4.7 to 8.6 months), with median progression-free survival and OS of 5.4 months (95% CI, 3.5 to 7.2 months) and 10.9 months (95% CI, 9.0 to 13.8 months), respectively. Key grade ≥ 3 treatment-related adverse events included neutropenia (35%), leukopenia (18%), anemia (14%), diarrhea (10%), and febrile neutropenia (10%), with 6% discontinuing treatment because of treatment-related adverse events.

CONCLUSION

SG is an active drug with a manageable safety profile with most common toxicities of neutropenia and diarrhea. SG has notable efficacy compared with historical controls in pretreated mUC that has progressed on both prior PLT regimens and CPI. The results from this study supported accelerated approval of SG in this population.

LncRNA-HOTAIR promotes endothelial cell pyroptosis by regulating the miR-22/NLRP3 axis in hyperuricaemia

Long non‐coding RNA (lncRNA) plays an important role in the renal inflammatory response caused by hyperuricaemia. However, the underlying molecular mechanisms through which lncRNA is involved in endothelial injury induced by hyperuricaemia remain unclear. In this study, we investigated the regulatory role of lncRNA‐HOTAIR in high concentration of uric acid (HUA)–induced renal injury. We established hyperuricaemia mouse model and an in vitro uric acid (UA)–induced human umbilical vein endothelial cell (HUVEC) injury model. In HUA‐treated HUVECs and hyperuricaemia mice, we observed increased HOTAIR and decreased miR‐22 expression. The expression of pyroptosis‐associated protein (NLRP3, Caspase‐1, GSDMD‐N, GSDMD‐FL) was increased. The release of LDH, IL‐1β and IL‐18 in cell supernatants and the sera of model mice was also increased. The proliferation of HUVECs stimulated by HUA was significantly inhibited, and the number of TUNEL‐positive cells in hyperuricaemia mouse kidney was increased. Bioinformatics analysis and luciferase reporter and RIP assays confirmed that HOTAIR promoted NLRP3 inflammasome activation by competitively binding miR‐22. In gain‐ or loss‐of‐function experiments, we found that HOTAIR and NLRP3 overexpression or miR‐22 knock down activated the NLRP3 inflammasome and promoted pyroptosis in HUA‐treated HUVECs, while NLRP3 and HOTAIR knockdown or a miR‐22 mimic exerted the opposite effects. Furthermore, in vivo experiments validated that HOTAIR knockdown alleviated renal inflammation in hyperuricaemia mice. In conclusion, we demonstrated that in hyperuricaemia, lncRNA‐HOTAIR promotes endothelial cell pyroptosis by competitively binding miR‐22 to regulate NLRP3 expression.

All-trans-retinoic acid suppresses rat embryo hindlimb bud mesenchymal chondrogenesis by modulating HoxD9 expression

In vertebrates, 5ʹ-Hoxd genes (Hoxd9), which are expressed in the hindlimb bud mesenchyme, participate in limb growth and patterning in early embryonic development. In the present study, We investigated the mechanisms by which ATRA regulates cultured E12.5 rat embryo hindlimb bud mesenchymal cells (rEHBMCs). Following exposure to ATRA over 24 h, mRNA and protein expression levels of HoxD9 were evaluated by reverse transcription-polymerase chain reaction (RT-PCR), quantitative real-time PCR (qPCR), and western blotting. Flow cytometry was used to detect apoptosis. ATRA inhibited the condensation and proliferation, and promoted the apoptosis rate of the rEHBMCs in a dose-dependent manner. Sox9 and Col2a1 in rEHBMCs were downregulated by ATRA in a dose-dependent manner at both mRNA and protein levels. Similarly, HoxD9 was downregulated by ATRA in a dose-dependent manner, in parallel with the cartilage-specific molecules Sox9 and Col2a1. Both qPCR and western blotting showed that both Shh and Gli3 were downregulated. Overexpression of HoxD9 reversed the effects of ATRA. These results demonstrate that ATRA suppresses chondrogenesis in rEHBMCs by inhibiting the expression of HoxD9 and its downstream protein targets, including Sox9 and Col2a1. This effect may also be correlated with inhibition of the Shh-Gli3 signaling pathway.

Expression characteristics of interferon-stimulated genes and possible regulatory mechanisms in lupus patients using transcriptomics analyses

Background

Type I interferon signature is one of the most important features of systemic lupus erythematosus (SLE), which indicates an active immune response to antigen invasion. Characteristics of type I interferon-stimulated genes (ISGs) in SLE patients have not been well described thus far.

Methods

We analyzed 35,842 cells of PBMC single-cell RNA sequencing data of five SLE patients and three healthy controls. Thereafter, 178 type I ISGs among DEGs of all cell clusters were screened based on the Interferome Database and AUCell package was used for ISGs activity calculation. To determine whether common ISG features exist in PBMCs and kidneys of patients with SLE, we analyzed kidney transcriptomic data from patients with lupus nephritis (LN) from the GEO database. MRL/lpr mice model were used to verify our findings.

Findings

We found that monocytes, B cells, dendritic cells, and granulocytes were significantly increased in SLE patients, while subsets of T cells were significantly decreased. Neutrophils and low-density granulocytes (LDGs) exhibited the highest ISG activity. GO and pathway enrichment analyses showed that DEGs focused on leukocyte activation, cell secretion, and pathogen infection. Thirty-one common ISGs were found expressed in both PBMCs and kidneys; these ISGs were also most active in neutrophils and LDGs. Transcription factors including PLSCR1, TCF4, IRF9 and STAT1 were found to be associated to ISGs expression. Consistently, we found granulocyte infiltration in the kidneys of MRL/lpr mice. Granulocyte inhibitor Avacopan reduced granulocyte infiltration and reversed renal conditions in MRL/lpr mice.

Interpretation

This study shows for the first time, the use of the AUCell method to describe ISG activity of granulocytes in SLE patients. Moreover, Avacopan may serve as a granulocyte inhibitor for treatment of lupus patients in the future.