Biomarkers of inflammation and repair in kidney disease progression

BCL2A1‑ and G0S2‑driven neutrophil extracellular traps: A protective mechanism linking preeclampsia to reduced breast cancer risk

Preeclampsia has been associated with a reduced risk of breast cancer (BC), but the mechanisms underlying this relationship remain unclear. It has been suggested that neutrophil extracellular traps (NETs), which are released upon neutrophil activation, play a key role in both preeclampsia and BC. To investigate this link, the single‑cell RNA sequencing dataset GSE173193 was analyzed and upregulated genes BCL2A1 and G0/G1 switch gene 2 (G0S2) were identified in neutrophils from preeclamptic placentas. These findings were validated using reverse transcription‑quantitative PCR and western blotting. Combined analyses of preeclampsia and BC tissues, from Gene Expression Omnibus (GSE24129) and The Cancer Genome Atlas databases respectively, identified 2,040 upregulated differentially expressed genes, including BCL2A1 and G0S2. Furthermore, these genes showed clinical relevance to BC, as demonstrated by Receiver Operating Characteristic curve, survival analyses and weighted gene co‑expression network analysis. Functional experiments revealed that overexpression of BCL2A1 and G0S2 increased NET release and inhibited BC cell proliferation, invasion and migration. The present study provides novel insights into the shared molecular pathways of preeclampsia and BC, emphasizing NETs as a potential protective mechanism as increased NET production in preeclampsia may contribute to a reduced BC risk by influencing tumor progression and offer avenues for further research into therapeutic interventions.

Unveiling mechanisms underlying kidney function changes during sex hormone therapy

BACKGROUNDMen with chronic kidney disease (CKD) experience faster kidney function decline than women. Studies in individuals undergoing sex hormone therapy suggest a role for sex hormones, as estimated glomerular filtration rate (eGFR) increases with feminizing therapy and decreases with masculinizing therapy. However, effects on measured GFR (mGFR), glomerular and tubular function, and involved molecular mechanisms remain unexplored.METHODSThis prospective, observational study included individuals initiating feminizing (estradiol and antiandrogens; n = 23) or masculinizing (testosterone; n = 21) therapy. Baseline and 3-month assessments included mGFR (iohexol clearance), kidney perfusion (para-aminohippuric acid clearance), tubular injury biomarkers, and plasma proteomics.RESULTSDuring feminizing therapy, mGFR and kidney perfusion increased (+3.6% and +9.1%, respectively; P < 0.05) without increased glomerular pressure. Tubular injury biomarkers, including urine neutrophil gelatinase-associated lipocalin, epidermal growth factor (EGF), monocyte chemoattractant protein-1, and chitinase 3-like protein 1 (YKL-40), decreased significantly (-53%, -42%, -45%, and -58%, respectively). During masculinizing therapy, mGFR and kidney perfusion remained unchanged, but urine YKL-40 and plasma tumor necrosis factor receptor 1 (TNFR-1) increased (+134% and +8%, respectively; P < 0.05). Proteomic analysis revealed differential expression of 49 proteins during feminizing and 356 proteins during masculinizing therapy. Many kidney-protective proteins were positively associated with estradiol and negatively associated with testosterone, including proteins involved in endothelial function (SFRP4, SOD3), inflammation reduction (TSG-6), and maintaining kidney tissue structure (agrin).CONCLUSIONSex hormones influence kidney physiology, with estradiol showing protective effects on glomerular and tubular function, while testosterone predominantly exerts opposing effects. These findings emphasize the role of sex hormones in sexual dimorphism observed in kidney function and physiology and suggest new approaches for sex-specific precision medicine.TRIAL REGISTRATIONDutch Trial Register (ID: NL9517); ClinicalTrials.gov (ID: NCT04482920).

NAT10 exacerbates acute renal inflammation by enhancing N4-acetylcytidine modification of the CCL2/CXCL1 axis

Inflammation plays an essential role in eliminating microbial pathogens and repairing tissues, while sustained inflammation accelerates kidney damage and disease progression. Therefore, understanding the mechanisms of the inflammatory response is vital for developing therapies for inflammatory kidney diseases like acute kidney injury (AKI), which currently lacks effective treatment. Here, we identified N-acetyltransferase 10 (NAT10) as an important regulator for acute inflammation. NAT10, the only known "writer" protein for N4-acetylcytidine (ac4C) acetylation, is elevated in renal tubules across various AKI models, human biopsies, and cultured tubular epithelial cells (TECs). Conditional knockout (cKO) of NAT10 in mouse kidneys attenuates renal dysfunction, inflammation, and infiltration of macrophages and neutrophils, whereas its conditional knock-in (cKI) exacerbates these effects. Mechanistically, our findings from ac4C-RIP-seq and RNA-seq analyses revealed that NAT10-mediated ac4C acetylation enhances the mRNA stability of a range of key chemokines, including C-C motif chemokine ligand 2 (CCL2) and C-X-C motif chemokine ligand 1(CXCL1), promoting macrophage and neutrophil recruitment and accelerating renal inflammation. Additionally, CCL2 and CXCL1 neutralizing antibodies or their receptor inhibitors, abrogated renal inflammation in NAT10-overexpression TECs or NAT10-cKI mice. Importantly, inhibiting NAT10, either through Adeno-associated virus 9 (AAV9)-mediated silencing or pharmacologically with our found inhibitor Cpd-155, significantly reduces renal inflammation and injury. Thus, targeting the NAT10/CCL2/CXCL1 axis presents a promising therapeutic strategy for treating inflammatory kidney diseases.

High Glucose-induced transcriptomic changes in human trabecular meshwork cells

Glaucoma is a leading cause of irreversible blindness, often associated with elevated intraocular pressure (IOP) due to trabecular meshwork (TM) dysfunction. Diabetes mellitus (DM) is recognized as a significant risk factor for glaucoma; however, the molecular mechanisms through which hyperglycemia affects TM function remain unclear. This study investigated the impact of high glucose on gene expression in human TM (HTM) cells to uncover pathways that contribute to TM dysfunction and glaucoma pathogenesis under diabetic conditions. Primary HTM cells were cultured under normoglycemic (5.5 mM) and hyperglycemic (30 mM) conditions for seven days, followed by mRNA sequencing (mRNA-seq) to identify differentially expressed genes, with quantitative PCR (qPCR) used for confirmatory analysis. STRING network analysis was performed to predict potential interactions among upregulated and downregulated genes. mRNA-seq analysis revealed 25 significantly differentially expressed genes in high glucose conditions, including upregulated genes associated with oxidative stress, apoptosis, autophagy, immune response, and fibrosis. Notably, TXNIP gene was significantly upregulated, indicating increased oxidative stress and apoptosis in TM cells, while downregulation of autophagy-related genes, such as HSPA6 and LAMP3, suggests compromised protein quality control. Immune response genes, including CCL7 and CHI3L1, were upregulated, suggesting an inflammatory response to oxidative stress. Increased expression of fibrosis-related genes, such as SNAI1, FGF7, and KRT19, and an increase in ECM proteins like Collagen 1 and FN accumulation and fibril formation suggest increased fibrosis of TM in diabetic conditions, potentially elevating IOP. Metabolic changes in diabetic patients could therefore lead to TM dysfunction, impair aqueous humor outflow, and elevate IOP, thereby increasing glaucoma risk. Targeting oxidative stress and fibrosis pathways offers therapeutic strategies to mitigate glaucoma progression in diabetic populations.

Associations of Urine Biomarkers During Ambulatory Acute Kidney Injury With Subsequent Recovery in Kidney Function: Findings From the SPRINT Study

RATIONALE & OBJECTIVE

Serum creatinine elevations in the ambulatory setting frequently occur during antihypertensive treatment and complicate clinical management, but few tools are available to distinguish whether kidney function will recover in this setting. This study evaluated if urine biomarkers of glomerular and tubular health are associated with subsequent recovery of eGFR after acute kidney injury (AKI) occurred in the ambulatory setting during blood pressure treatment.

STUDY DESIGN

Longitudinal analysis of clinical trial participants.

SETTING & PARTICIPANTS

652 participants in the Systolic Blood Pressure Intervention Trial (SPRINT) who developed AKI in the ambulatory setting, defined as a rise in serum creatinine of ≥0.3 mg/dL from baseline detected at the 1-year or 2-year study visits.

EXPOSURE

Eight urine biomarkers measured at baseline and at the study visit when ambulatory AKI was detected.

OUTCOME

<50% recovery in eGFR ("non-recovery") at 12-months.

ANALYTICAL APPROACH

Multivariable logistic regression models, stratified by randomization arm, to evaluate biomarker associations with the odds of non-recovery in eGFR.

RESULTS

Mean age was 70 ±10 years; eGFR at baseline was 62 ± 25 mL/min/1.73 m2, and eGFR at the time of serum creatinine elevation was 42 ± 12 mL/min/1.73 m2. Among biomarkers measured at the time ambulatory AKI was detected, higher urine albumin (OR per 1-SD higher: 1.72; 95% CI: 1.10, 2.70) and lower epidermal growth factor (OR 0.46; 95% CI: 0.26, 0.79) were associated with non-recovery in the standard BP treatment arm; higher urine α-1 microglobulin (OR 1.45; 1.09, 1.92), lower epidermal growth factor (OR 0.62; 95% CI: 0.46, 0.83) and lower kidney injury molecule-1 (OR 0.75; 95% CI: 0.59, 0.96) were associated with non-recovery of eGFR in the intensive BP treatment arm.

LIMITATIONS

Persons with diabetes and proteinuria >1 g/d were excluded.

CONCLUSIONS

Among adults enrolled in a BP treatment trial who developed ambulatory AKI, urine biomarkers reflecting glomerular injury and tubular dysfunction may help to distinguish whether kidney function will subsequently recover.

PLAIN-LANGUAGE SUMMARY

Elevations in serum creatinine can occur when treating hypertension and complicate clinical management, but there are few tools available to distinguish whether an individual's kidney function will subsequently recover. In this study, we investigated the association of kidney biomarkers measured in the urine with subsequent kidney function among individuals in the outpatient setting who develop a rise in serum creatinine. We found that biomarkers reflecting worse glomerular injury and tubular dysfunction are associated with the risk of an individual's kidney function not recovering. These results suggest that a broader assessment of kidney health when serum creatinine increases in the outpatient setting may help distinguish subsequent trajectories in kidney function.

C-FOS promotes the formation of neutrophil extracellular traps and the recruitment of neutrophils in lung metastasis of triple-negative breast cancer

BACKGROUND

Neutrophil extracellular traps (NETs) are composed of DNA chains from neutrophils and associated proteolytic enzymes, which play an important role in cancer metastasis. However, the molecular mechanism of NET-mediated lung metastasis in triple-negative breast cancer (TNBC) remains unclear.

METHODS

The expression levels of NETs in breast cancer specimens and serum were analyzed and compared with normal samples. Single-cell sequencing bioinformatics analysis was conducted to identify differentially expressed genes and functional enrichment related to NET formation in patients with breast cancer. The effects of c-FOS on neutrophil recruitment and NET formation in TNBC were investigated. The upstream and downstream regulatory mechanisms mediated by c-FOS were explored through in vitro and in vivo experiments. Therapeutic approaches targeting c-FOS for treating TNBC were further studied.

RESULTS

Inhibition of c-FOS can suppress tumor growth and lung metastasis in TNBC. Mechanistically, c-FOS promotes transcription by binding to the PAD4 promoter region, facilitating the formation of NETs. Additionally, the activation of the ROS-p38 pathway further enhances c-FOS expression. High expression of c-FOS also promotes the expression of inflammatory factors, facilitating neutrophil recruitment. Both in vitro and in vivo experiments demonstrated that the application of T5224 effectively inhibits the formation of NETs, suppressing lung metastasis and tumor growth.

CONCLUSION

In summary, this study demonstrates that the ROS-p38-cFOS-PAD4 axis can increase NET formation in TNBC and promote the expression of inflammatory factors, facilitating neutrophil recruitment. Therefore, targeting this pathway may help inform new therapeutic strategies and provide new insights for immunotherapy in TNBC.

Identifying proteins and pathways associated with multimorbidity in 53,026 adults

BACKGROUND AND AIMS

Multimorbidity, the coexistence of multiple chronic diseases, is a rapidly expanding global health challenge, carrying profound implications for patients, caregivers, healthcare systems, and society. Investigating the determinants and drivers underlying multiple chronic diseases is a priority for disease management and prevention.

METHOD

This prospective cohort study analyzed data from the 53,026 participants in the UK Biobank from baseline (2006 to 2010) across 13.3 years of follow-up. Using Cox proportional hazards regression model, we characterized shared and unique associations across 38 incident outcomes (31 chronic diseases, 6 system mortality and all-cause mortality). Furthermore, ordinal regression models were used to assess the association between protein levels and multimorbidity (0-1, 2, 3-4, or ≥ 5 chronic diseases). Functional and tissue enrichment analysis were employed for multimorbidity-associated proteins. The upstream regulators of above proteins were identified.

RESULTS

We demonstrated 972 (33.3 %) proteins were shared across at least two incident chronic diseases after Bonferroni correction (P < 3.42 × 10-7, 93.3 % of those had consistent effects directions), while 345 (11.8 %) proteins were uniquely linked to a single chronic disease. Remarkably, GDF15, PLAUR, WFDC2 and AREG were positively associated with 20-24 incident chronic diseases (hazards ratios: 1.21-3.77) and showed strong associations with multimorbidity (odds ratios: 1.33-1.89). We further identified that protein levels are explained by common risk factors, especially renal function, liver function, inflammation, and obesity, providing potential intervention targets. Pathway analysis has underscored the pivotal role of the immune response, with the top three transcription factors associated with proteomics being NFKB1, JUN and RELA.

CONCLUSIONS

Our results enhance the understanding of the biological basis underlying multimorbidity, offering biomarkers for disease identification and novel targets for therapeutic intervention.

Deceased donor urinary Dickkopf-3 associates with future allograft function following kidney transplantation

Predicting future kidney allograft function is challenging. Novel biomarkers, such as urinary Dickkopf-3 (uDKK3), may help guide donor selection and improve allograft outcomes. In this prospective multicenter pilot trial, we investigated whether donor uDKK3 reflects organ quality and is associated with future allograft function. We measured uDKK3/crea ratios (uDKK3/crea) from 95 deceased and 46 living kidney donors. Prenephrectomy uDKK3/crea levels were 100× higher in deceased than in living donors (9888 pg/mg vs 113 pg/mg; P < .001). Among deceased donor transplantations, recipients were stratified by their corresponding uDKK3/crea donor levels ranging below (group A, n = 68) or above (group B, n = 65) median. The primary end point of best estimated glomerular filtration rate (eGFR) within the first 3 months after kidney transplantation was superior in group A (56.3 mL/min/1.73 m2) than that in group B (44.2 mL/min/1.73 m2; P = .0139). Second, the composite clinical end point consisting of death, allograft failure or eGFR decline >50% occurred less frequent in group A. By mixed linear regression modeling, donor uDKK3/crea remained an independent predictor of eGFR after transplantation, with a slope of -4.282 mL/min/1.73 m2 per logarithmic increase in donor uDKK3/crea. In summary, uDKK3 may serve as a noninvasive, donor-dependent biomarker for assessing organ quality and future allograft function.

Midkine, a novel MCP-1 activator mediated PM2.5-aggravated experimental pulmonary fibrosis

Exposure to fine particulate matter (PM2.5) is associated with increased morbidity and mortality among patients with idiopathic pulmonary fibrosis (IPF). Pathological alterations in IPF typically originate in the subpleural regions of the lungs. However, it was unclear how PM2.5 affected subpleural pulmonary fibrosis. In this study, atmospheric PM2.5 and carbon blacks were utilized as representative particulate matter to investigate these effects. Mouse models and cell models were made to investigate macrophage chemotaxis changes under PM2.5 exposure in vivo and in vitro. The findings indicated that PM2.5 promoted macrophage aggregation in the subpleural region of lung and aggravated bleomycin-induced pulmonary fibrosis in mice. At the same time, we uncovered for the first time that PM2.5 exposure led to an upregulation of midkine, which subsequently enhanced the production of monocyte chemotactic protein-1 (MCP-1) through the cell surface receptor Syndecan 4 (SDC4) in pleural mesothelial cells (PMCs), thereby, inducing macrophage aggregation in subpleural region of lung. Furthermore, our results indicated that PM2.5 and bleomycin facilitated macrophage M1 polarization and the production of profibrotic inflammatory factors, culminating in fibrotic alterations in PMCs, lung fibroblasts, and alveolar epithelial cells. Finally, we demonstrated that inhibition of midkine ameliorated lung function and mitigated pulmonary fibrosis in vivo. In conclusion, our findings elucidated that midkine acted as a novel MCP-1 activator, mediating PM2.5-aggravated experimental pulmonary fibrosis, and suggested that the midkine/SDC4/MCP-1 signal should be a new therapeutic target for the treatment of PM2.5-related IPF.

Huangqi-Danshen decoction alleviates renal fibrosis through targeting SCD1 to modulate cGAS/STING signaling

ETHNOPHARMACOLOGICAL RELEVANCE

The Huangqi-Danshen decoction (HDD) is composed of Huangqi (Astragali Radix) and Danshen (Salviae Miltiorrhizae Radix et Rhizoma) and has been shown to alleviate renal fibrosis. However, the potential therapeutic mechanisms and effective components of HDD remain unclear.

AIM OF THE STUDY

Both lipid metabolism and cGAS/STING signaling play vital roles in the development and progression of renal fibrosis. However, their relationship in renal fibrosis is largely unknown. The present study aimed to investigate the antifibrotic mechanisms of HDD from the perspective of lipid remodeling and cGAS/STING signaling.

MATERIALS AND METHODS

In vivo, renal fibrosis was induced by feeding male C57BL/6 mice with 0.2% adenine-diet for 28 consecutive days. The treatment groups were orally administered HDD at low, medium, and high doses of 3.4 g/kg/d, 6.8 g/kg/d, and 13.6 g/kg/d simultaneously with modeling. Renal function was evaluated by the serum levels of urea nitrogen and creatinine, pathological changes of renal tissue were evaluated by Periodic acid-Schiff and Masson's trichrome staining, and renal lipid metabolites were analyzed by lipidomics. Western blotting, immunohistochemistry, and immunofluorescence were used to detect the expressions of fibrosis-related proteins, SCD1, and cGAS/STING signaling-related proteins in renal tissue. In vitro, mouse primary proximal tubular epithelial cells (PTECs) were treated with transforming growth factor-β1 (TGF-β1) or stearoyl-CoA desaturase 1 (SCD1) inhibitor A939572. Additionally, UHPLC-QE-MS analysis and TCMSP database were used to screen the effective components of HDD, and the action mechanisms of these components were verified in mouse primary PTECs.

RESULTS

HDD dose-dependently improved renal function, pathological injury, and fibrosis in adenine-induced chronic kidney disease (CKD) mice model. Moreover, cGAS/STING signaling was significantly activated in fibrotic kidney and was suppressed by HDD treatment. In renal lipidomics analysis, 521 and 138 differential lipids were identified in control vs. CKD and CKD vs. CKD + HDD, respectively. Of note, lipids increased in fibrotic kidneys were more saturated (fewer double bonds), whereas lipids increased by HDD were less saturated (more double bonds). Further, SCD1 expression was significantly down-regulated in fibrotic kidney and could be restored by HDD treatment. The expression of SCD1 was also down-regulated in Ju CKD patients' dataset and TGF-β1-induced fibrogenic responses in mouse primary PTECs. Mechanistically, specific inhibition of SCD1 expression could activate cGAS/STING signaling in primary PTECs. In addition, three components of HDD (isoimperatorin, baicalin, and miltirone) were screened out. Furthermore, administration of these three components, especially isoimperatorin and miltirone, counteracted the activation of cGAS/STING signaling induced by SCD1 pharmacological inhibition.

CONCLUSION

HDD could alleviate renal fibrosis, which may be related to the regulation of cGAS/STING signaling through targeting SCD1.

Bioinformatics approach reveals the critical role of inflammation-related genes in age-related hearing loss

Age-related hearing loss (ARHL) is the most prevalent sensory impairment in the elderly. However, the pathogenesis of ARHL remains unclear. This study was aimed to explore the potential inflammation-related genes of ARHL and suggest novel therapeutic targets for this condition. Initially, a total of 105 Inflammatory related differentially expressed genes (IRDEGs) were obtained by overlapping the differentially expressed genes from the GSE49522 and GSE49543 datasets with Inflammatory related genes. The IRDEGs were mainly enriched in MAPK, PI3K-Akt, Hippo and JAK-STAT pathways by analysis of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. We then identified 10 key IRDEGs including Alox5ap, Chil1, Clec7a, Dysf, Fcgr3, etc. using Least absolute shrinkage and selection operator regression analysis and converted them into human genes. The ROC curve indicated that Alox5ap expression presented a high accuracy in distinguishing between different groups. By CIBERSORT algorithm, 8 humanized key IRDEGs were correlated with the infiltration abundance of 3 immune cells. Finally, it showed that the Alox5ap expression was significantly more effective compared to other variables in the diagnostic model of ARHL. This study suggests that inflammation might play a role in the development of ARHL, providing a deeper understanding of the underlying causes of this disease.

Acute kidney injury

Acute kidney injury (AKI) is a common, heterogeneous, multifactorial condition, which is part of the overarching syndrome of acute kidney diseases and disorders. This condition's incidence highest in low-income and middle-income countries. In the short term, AKI is associated with increased mortality, an increased risk of complications, extended stays in hospital, and high health-care costs. Long-term complications include chronic kidney disease, kidney failure, cardiovascular morbidity, and an increased risk of death. Several strategies are available to prevent and treat AKI in specific clinical contexts. Otherwise, AKI care is primarily supportive, focused on treatment of the underlying cause, prevention of further injury, management of complications, and short-term renal replacement therapy in case of refractory complications. Evidence confirming that AKI subphenotyping is necessary to identify precision-oriented interventions is growing. Long-term follow-up of individuals recovered from AKI is recommended but the most effective models of care remain unclear.

High Glucose-Induced Transcriptomic Changes in Human Trabecular Meshwork Cells

Glaucoma is a leading cause of irreversible blindness, often associated with elevated intraocular pressure (IOP) due to trabecular meshwork (TM) dysfunction. Diabetes mellitus (DM) is recognized as a significant risk factor for glaucoma; however, the molecular mechanisms through which hyperglycemia affects TM function remain unclear. This study investigated the impact of high glucose on gene expression in human TM (HTM) cells to uncover pathways that contribute to TM dysfunction and glaucoma pathogenesis under diabetic conditions. Primary HTM cells were cultured under normoglycemic (5.5 mM) and hyperglycemic (30 mM) conditions for seven days, followed by mRNA sequencing (mRNA-seq) to identify differentially expressed genes, with quantitative PCR (qPCR) used for confirmatory analysis. STRING network analysis was performed to predict interactions among upregulated and downregulated proteins. mRNA-seq analysis revealed 25 significantly differentially expressed genes in high glucose conditions, including upregulated genes associated with oxidative stress, apoptosis, autophagy, immune response, and fibrosis. Notably, TXNIP was significantly upregulated, indicating increased oxidative stress and apoptosis in TM cells, while downregulation of autophagy-related genes, such as HSPA6 and LAMP3, suggests compromised protein quality control. Immune response genes, including CCL7 and CHI3L1, were upregulated, suggesting an inflammatory response to oxidative stress. Increased expression of fibrosis-related genes, such as SNAI1, FGF7, and KRT19, supports the hypothesis of ECM accumulation in diabetic conditions, potentially elevating IOP. Chronic hyperglycemia in diabetic patients could therefore lead to TM dysfunction, impair aqueous humor outflow, and elevate IOP, thereby increasing glaucoma risk. Targeting oxidative stress and fibrosis pathways offers therapeutic strategies to mitigate glaucoma progression in diabetic populations.

Inflammatory Effects and Regulatory Mechanisms of Chitinase-3-like-1 in Multiple Human Body Systems: A Comprehensive Review

Chitinase-3-like-1 (Chi3l1), also known as YKL-40 or BRP-39, is a highly conserved mammalian chitinase with a chitin-binding ability but no chitinase enzymatic activity. Chi3l1 is secreted by various cell types and induced by several inflammatory cytokines. It can mediate a series of cell biological processes, such as proliferation, apoptosis, migration, differentiation, and polarization. Accumulating evidence has verified that Chi3l1 is involved in diverse inflammatory conditions; however, a systematic and comprehensive understanding of the roles and mechanisms of Chi3l1 in almost all human body system-related inflammatory diseases is still lacking. The human body consists of ten organ systems, which are combinations of multiple organs that perform one or more physiological functions. Abnormalities in these human systems can trigger a series of inflammatory environments, posing serious threats to the quality of life and lifespan of humans. Therefore, exploring novel and reliable biomarkers for these diseases is highly important, with Chi3l1 being one such parameter because of its physiological and pathophysiological roles in the development of multiple inflammatory diseases. Reportedly, Chi3l1 plays an important role in diagnosing and determining disease activity/severity/prognosis related to multiple human body system inflammation disorders. Additionally, many studies have revealed the influencing factors and regulatory mechanisms (e.g., the ERK and MAPK pathways) of Chi3l1 in these inflammatory conditions, identifying potential novel therapeutic targets for these diseases. In this review, we comprehensively summarize the potential roles and underlying mechanisms of Chi3l1 in inflammatory disorders of the respiratory, digestive, circulatory, nervous, urinary, endocrine, skeletal, muscular, and reproductive systems, which provides a more systematic understanding of Chi3l1 in multiple human body system-related inflammatory diseases. Moreover, this article summarizes potential therapeutic strategies for inflammatory diseases in these systems on the basis of the revealed roles and mechanisms mediated by Chi3l1.

Enriched human embryonic stem cells-derived CD133+, CD24+ renal progenitors engraft and restore function in a gentamicin-induced kidney injury in mice

Introduction

Acute kidney injury (AKI) is a common health problem that leads to high morbidity and potential mortality. The failure of conventional treatments to improve forms of this condition highlights the need for innovative and effective treatment approaches. Regenerative therapies with Renal Progenitor Cells (RPCs) have been proposed as a promising new strategy. A growing body of evidence suggests that progenitor cells differentiated from different sources, including human embryonic stem cells (hESCs), can effectively treat AKI.

Methods

Here, we describe a method for generating RPCs and directed human Embryoid Bodies (EBs) towards CD133+CD24+ renal progenitor cells and evaluate their functional activity in alleviating AKI.

Results

The obtained results show that hESCs-derived CD133+CD24+ RPCs can engraft into damaged renal tubules and restore renal function and structure in mice with gentamicin-induced kidney injury, and significantly decrease blood urea nitrogen levels, suppress oxidative stress and inflammation, and attenuate histopathological disturbances, including tubular necrosis, tubular dilation, urinary casts, and interstitial fibrosis.

Conclusion

The results suggest that RPCs have a promising regenerative potential in improving renal disease and can lay the foundation for future cell therapy and disease modeling.

Advances in uromodulin biology and potential clinical applications

Uromodulin (also known as Tamm-Horsfall protein) is a kidney-specific glycoprotein secreted bidirectionally into urine and into the circulation, and it is the most abundant protein in normal urine. Although the discovery of uromodulin predates modern medicine, its significance in health and disease has been rather enigmatic. Research studies have gradually revealed that uromodulin exists in multiple forms and has important roles in urinary and systemic homeostasis. Most uromodulin in urine is polymerized into highly organized filaments, whereas non-polymeric uromodulin is detected both in urine and in the circulation, and can have distinct roles. The interactions of uromodulin with the immune system, which were initially reported to be a key role of this protein, are now better understood. Moreover, the discovery that uromodulin is associated with a spectrum of kidney diseases, including acute kidney injury, chronic kidney disease and autosomal-dominant tubulointerstitial kidney disease, has further accelerated investigations into the role of this protein. These discoveries have prompted new questions and ushered in a new era in uromodulin research. Here, we delineate the latest discoveries in uromodulin biology and its emerging roles in modulating kidney and systemic diseases, and consider future directions, including its potential clinical applications.

Associations of Urine Epidermal Growth Factor With Kidney and Cardiovascular Outcomes in Individuals With CKD in SPRINT

Introduction

Urine epidermal growth factor (uEGF) has been found to be inversely associated with kidney function loss, whereas its associations with cardiovascular disease (CVD) and mortality have not been studied.

Methods

We measured baseline uEGF levels among 2346 Systolic Blood Pressure Intervention Trial (SPRINT) participants with an estimated glomerular filtration rate (eGFR) < 60 ml/min per 1.73 m2. A linear mixed-effects model was used to investigate the associations of uEGF with the annual eGFR change; Cox proportional hazards regression models were used to analyze its associations with the ≥30% eGFR decline, CVD, and all-cause mortality outcomes. To account for the competing risk of death, the Fine and Gray method was utilized for acute kidney injury (AKI) and end-stage kidney disease (ESKD) outcomes.

Results

At baseline, the study participants had mean age of 73 ± 9 years, mean eGFR of 46 ± 11 ml/min per 1.73 m2, and median urine albumin-to-creatinine ratio (UACR) of 15 mg/g (interquartile range: 7-49). In the multivariable-adjusted analysis including baseline urine albumin and eGFR, each 50% lower uEGF concentration was associated with 0.74% (95% confidence interval [CI]: 0.29-1.19) per year faster decline in eGFR and 1.17 times higher risk of ≥30% eGFR decline (95% CI: 1.00-1.36). Lower uEGF concentrations were found to be associated with increased risks of ESKD, AKI, CVD, and all-cause mortality; however, these associations did not reach statistical significance when the models were controlled for baseline urine albumin and eGFR.

Conclusion

Among hypertensive adults with chronic kidney disease (CKD), lower baseline uEGF concentration was associated with faster eGFR decline independent of baseline albuminuria and eGFR; but not with ESKD, AKI, CVD, and all-cause mortality.

Proteomic Analysis Identifies Dysregulated Proteins in Albuminuria: A South African Pilot Study

Albuminuria may precede decreases in the glomerular filtration rate (GFR) and both tests are insensitive predictors of early stages of kidney disease. Our aim was to characterise the urinary proteome in black African individuals with albuminuria and well-preserved GFR from South Africa. This case-controlled study compared the urinary proteomes of 52 normoalbuminuric (urine albumin: creatinine ratio (uACR) < 3 mg/mmol) and 56 albuminuric (uACR ≥ 3 mg/mmol) adults of black African ethnicity. Urine proteins were precipitated, reduced, alkylated, digested, and analysed using an Evosep One LC (Evosep Biosystems, Odense, Denmark) coupled to a Sciex 5600 Triple-TOF (Sciex, Framingham, MA, USA) in data-independent acquisition mode. The data were searched on SpectronautTM 15. Differentially abundant proteins (DAPs) were filtered to include those with a ≥2.25-fold change and a false discovery rate ≤ 1%. Receiver-operating characteristic curves were used to assess the discriminating abilities of proteins of interest. Pathway analysis was performed using Enrichr software. As expected, the albuminuric group had higher uACR (7.9 vs. 0.55 mg/mmol, p < 0.001). The median eGFR (mL/min/1.73 m2) showed no difference between the groups (111 vs. 114, p = 0.707). We identified 80 DAPs in the albuminuria group compared to the normoalbuminuria group, of which 59 proteins were increased while 21 proteins were decreased in abundance. We found 12 urinary proteins with an AUC > 0.8 and a p < 0.001 in the multivariate analysis. Furthermore, an 80-protein model was developed that showed a high AUC ˃ 0.907 and a predictive accuracy of 91.3% between the two groups. Pathway analysis found that the DAPs were involved in insulin growth factor (IGF) functions, innate immunity, platelet degranulation, and extracellular matrix organization. In albuminuric individuals with a well-preserved eGFR, pathways involved in preventing the release and uptake of IGF by insulin growth factor binding protein were significantly enriched. These proteins are indicative of a homeostatic imbalance in a variety of cellular processes underlying renal dysfunction and are implicated in chronic kidney disease.

Clinical Factors and Biomarkers Associated with Depressive Disorders in Older Patients Affected by Chronic Kidney Disease (CKD): Does the Advanced Glycation End Products (AGEs)/RAGE (Receptor for AGEs) System Play Any Role?

Depressive disorders are highly prevalent among subjects suffering from chronic kidney disease (CKD). The aim of the present study is to evaluate clinical and biochemical factors associated with depressive disorders in a sample of older CKD patients, with a focus on advanced glycation end products (AGEs) and their soluble receptors (sRAGEs). A total of 115 older subjects affected by CKD (stages 3 to 5, not in dialysis) were selected for this study. These patients were divided into two groups according to the presence of depressive disorders defined by a score ≥ 10 on the 30-item Geriatric Depression Scale (GDS). The two groups were compared by independent sample t tests for continuous variables and χ2 tests for qualitative ones. Significant variables at univariate analyses were then inserted as predictors of a binary logistic regression model, with the presence or absence of depressive disorders as a dependent variable. The binary logistic regression model showed that patients with concomitant depressive disorders were more frequently of female gender (p < 0.01) and had lower MCP1 (p < 0.01) and AGE circulating levels (p < 0.01) than their counterparts. Depressive disorders in older CKD patients are more prevalent in women and seem to be inversely associated with systemic inflammation and circulating AGEs.

Uncovering novel mechanisms of chitinase-3-like protein 1 in driving inflammation-associated cancers

Chitinase-3-like protein 1 (CHI3L1) is a secreted glycoprotein that is induced and regulated by multiple factors during inflammation in enteritis, pneumonia, asthma, arthritis, and other diseases. It is associated with the deterioration of the inflammatory environment in tissues with chronic inflammation caused by microbial infection or autoimmune diseases. The expression of CHI3L1 expression is upregulated in several malignant tumors, underscoring the crucial role of chronic inflammation in the initiation and progression of cancer. While the precise mechanism connecting inflammation and cancer is unclear, the involvement of CHI3L1 is involved in chronic inflammation, suggesting its role as a contributing factor to in the link between inflammation and cancer. CHI3L1 can aggravate DNA oxidative damage, induce the cancerous phenotype, promote the development of a tumor inflammatory environment and angiogenesis, inhibit immune cells, and promote cancer cell growth, invasion, and migration. Furthermore, it participates in the initiation of cancer progression and metastasis by binding with transmembrane receptors to mediate intracellular signal transduction. Based on the current research on CHI3L1, we explore introduce the receptors that interact with CHI3L1 along with the signaling pathways that may be triggered during chronic inflammation to enhance tumorigenesis and progression. In the last section of the article, we provide a brief overview of anti-inflammatory therapies that target CHI3L1.

Biomarkers of chronic kidney disease in older individuals: navigating complexity in diagnosis

Chronic kidney disease (CKD) in older individuals is a matter of growing concern in the field of public health across the globe. Indeed, prevalence of kidney function impairment increases with advancing age and is often exacerbated by age-induced modifications of kidney function, presence of chronic diseases such as diabetes, hypertension, and cardiovascular disorders, and increased burden related to frailty, cognitive impairment and sarcopenia. Accurate assessment of CKD in older individuals is crucial for timely intervention and management and relies heavily on biomarkers for disease diagnosis and monitoring. However, the interpretation of these biomarkers in older patients may be complex due to interplays between CKD, aging, chronic diseases and geriatric syndromes. Biomarkers such as serum creatinine, estimated glomerular filtration rate (eGFR), and albuminuria can be significantly altered by systemic inflammation, metabolic changes, and medication use commonly seen in this population. To overcome the limitations of traditional biomarkers, several innovative proteins have been investigated as potential, in this review we aimed at consolidating the existing data concerning the geriatric aspects of CKD, describing the challenges and considerations in using traditional and innovative biomarkers to assess CKD in older patients, highlighting the need for integration of the clinical context to improve biomarkers' accuracy.

Associations of Intact and C-Terminal FGF23 with Inflammatory Markers in Older Patients Affected by Advanced Chronic Kidney Disease

Background: In patients with chronic kidney disease (CKD), Fibroblast Growth Factor 23 (FGF23) is markedly increased and has been proposed to interact with systemic inflammation. Methods: In this cross-sectional study, we evaluated the correlations of intact FGF23, c-terminal FGF23, and the FGF23 ratio (c-terminal to intact) with some inflammatory cytokines in 111 elderly patients with advanced CKD not yet in dialysis. Results: Estimated glomerular filtration rate (eGFR) was inversely correlated with intact FGF23 and c-terminal FGF23, as well as with interleukin 6 (IL-6), tumor necrosis factor alpha (TNFα), and monocyte chemoattractant protein-1 (MCP-1). Intact FGF23 levels were directly correlated with IL-6 (r = 0.403; p < 0.001) and TNFα (r = 0.401; p < 0.001) while c-terminal FGF23 was directly correlated with MCP-1 (r = 0.264; p = 0.005). The FGF23 ratio was, instead, inversely correlated with IL-6 (r = -0.326; p < 0.001). Multivariate analysis revealed that intact FGF23 was directly associated with TNFα [B = 0.012 (95% CI 0.006, 0.019); p = 0.003] and c-terminal FGF23 was directly associated with MCP-1 [B = 0.001 (95% CI 0.000, 0.002); p = 0.038], while the FGF23 ratio was inversely correlated with IL-6 [B = -0.028 (95% CI -0.047, -0.010); p = 0.002]. Conclusions: Our data demonstrate that, in CKD patients, intact FGF23 and the metabolites deriving from its proteolytic cleavage are differently associated with some inflammatory pathways. In particular, intact FGF23 is mainly associated with IL-6 and TNFα, c-terminal FGF23 with MCP-1, and the FGF23 ratio with IL6.

Multi-omics analysis of kidney tissue metabolome and proteome reveals the protective effect of sheep milk against adenine-induced chronic kidney disease in mice

Chronic kidney disease (CKD) is characterized by impaired renal function and is associated with inflammation, oxidative stress, and fibrosis. Sheep milk contains several bioactive molecules with protective effects against inflammation and oxidative stress. In the current study, we investigated the potential renoprotective effects of sheep milk and the associated mechanisms of action in an adenine-induced CKD murine model. Sheep milk delayed renal chronic inflammation (e.g., significant reduction in levels of inflammatory factors Vcam1, Icam1, Il6, and Tnfa), fibrosis (significant reduction in levels of fibrosis factors Col1a1, Fn1, and Tgfb), oxidative stress (significant increase in levels of antioxidants and decrease in oxidative markers), mineral disorders, and renal injury in adenine-treated mice (e.g. reduced levels of kidney injury markers NGAL and KIM-1). The combined proteomics and metabolomics analyses showed that sheep milk may affect the metabolic processes of several compounds, including proteins, lipids, minerals, and hormones in mice with adenine-induced chronic kidney disease. In addition, it may regulate the expression of fibrosis-related factors and inflammatory factors through the JAK1/STAT3/HIF-1α signaling pathway, thus exerting its renoprotective effects. Therefore, sheep milk may be beneficial for patients with CKD and should be evaluated in preclinical and clinical studies.

Association of urinary excretion rates of uric acid with biomarkers of kidney injury in patients with advanced chronic kidney disease

BACKGROUND

The potential influence of hyperuricemia on the genesis and progression of chronic kidney disease (CKD) remains controversial. In general, the correlation between blood levels of uric acid (UA) and the rate of progression of CKD is considered to be modest, if any, and the results of relevant trials oriented to disclose the effect of urate-lowering therapies on this outcome have been disappointing. Urinary excretion rates of UA could reflect more accurately the potential consequences of urate-related kidney injury.

METHOD

Using a cross-sectional design, we investigated the correlation between different estimators of the rates of urinary excretion of UA (total 24-hour excretion, mean urinary concentration, renal clearance and fractional excretion)(main study variables), on one side, and urinary levels of selected biomarkers of kidney injury and CKD progression (DKK3, KIM1, NGAL, interleukin 1b and MCP)(main outcome variables), in 120 patients with advanced CKD (mean glomerular filtration rate 21.5 mL/minute). We took into consideration essential demographic, clinical and analytic variables with a potential confounding effect on the explored correlations (control variables). Spearman's rho correlation and nonlinear generalized additive regression models (GAM) with p-splines smoothers were used for statistical analysis.

MAIN RESULTS

Multivariate analysis disclosed independent correlations between urinary UA concentrations, clearances and fractional excretion rates (but not plasma UA or total 24-hour excretion rates of UA), on one side, and the scrutinized markers. These correlations were more consistent for DKK3 and NGAL than for the other biomarkers. Glomerular filtration rate, proteinuria and treatment with statins or RAA axis antagonists were other independent correlates of the main outcome variables.

CONCLUSIONS

Our results support the hypothesis that urinary excretion rates of UA may represent a more accurate marker of UA-related kidney injury than plasma levels of this metabolite, in patients with advanced stages of CKD. Further, longitudinal studies will be necessary, to disclose the clinical significance of these findings.

Epidemiology and Clinical Outcomes of Community-Acquired Acute Kidney Injury in the Emergency Department: A Multisite Retrospective Cohort Study

RATIONALE & OBJECTIVE

The prevalence of community-acquired acute kidney injury (CA-AKI) in the United States and its clinical consequences are not well described. Our objective was to describe the epidemiology of CA-AKI and the associated clinical outcomes.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

178,927 encounters by 139,632 adults at 5 US emergency departments (EDs) between July 1, 2017, and December 31, 2022.

PREDICTORS

CA-AKI identified using KDIGO (Kidney Disease: Improving Global Outcomes) serum creatinine (Scr)-based criteria.

OUTCOMES

For encounters resulting in hospitalization, the in-hospital trajectory of AKI severity, dialysis initiation, intensive care unit (ICU) admission, and death. For all encounters, occurrence over 180 days of hospitalization, ICU admission, new or progressive chronic kidney disease, dialysis initiation, and death.

ANALYTICAL APPROACH

Multivariable logistic regression analysis to test the association between CA-AKI and measured outcomes.

RESULTS

For all encounters, 10.4% of patients met the criteria for any stage of AKI on arrival to the ED. 16.6% of patients admitted to the hospital from the ED had CA-AKI on arrival to the ED. The likelihood of AKI recovery was inversely related to CA-AKI stage on arrival to the ED. Among encounters for hospitalized patients, CA-AKI was associated with in-hospital dialysis initiation (OR, 6.2; 95% CI, 5.1-7.5), ICU admission (OR, 1.9; 95% CI, 1.7-2.0), and death (OR, 2.2; 95% CI, 2.0-2.5) compared with patients without CA-AKI. Among all encounters, CA-AKI was associated with new or progressive chronic kidney disease (OR, 6.0; 95% CI, 5.6-6.4), dialysis initiation (OR, 5.1; 95% CI, 4.5-5.7), subsequent hospitalization (OR, 1.1; 95% CI, 1.1-1.2) including ICU admission (OR, 1.2; 95% CI, 1.1-1.4), and death (OR, 1.6; 95% CI, 1.5-1.7) during the subsequent 180 days.

LIMITATIONS

Residual confounding. Study implemented at a single university-based health system. Potential selection bias related to exclusion of patients without an available baseline Scr measurement. Potential ascertainment bias related to limited repeat Scr data during follow-up after an ED visit.

CONCLUSIONS

CA-AKI is a common and important entity that is associated with serious adverse clinical consequences during the 6-month period after diagnosis.

PLAIN-LANGUAGE SUMMARY

Acute kidney injury (AKI) is a condition characterized by a rapid decline in kidney function. There are many causes of AKI, but few studies have examined how often AKI is already present when patients first arrive to an emergency department seeking medical attention for any reason. We analyzed approximately 175,000 visits to Johns Hopkins emergency departments and found that AKI is common on presentation to the emergency department and that patients with AKI have increased risks of hospitalization, intensive care unit admission, development of chronic kidney disease, requirement of dialysis, and death in the first 6 months after diagnosis. AKI is an important condition for health care professionals to recognize and is associated with serious adverse outcomes.

Single-cell and bulk RNA sequencing reveal heterogeneity and diagnostic markers in papillary thyroid carcinoma lymph-node metastasis

PURPOSE

Papillary thyroid carcinoma (PTC) is characterized by lymph-node metastasis (LNM), which affects recurrence and prognosis. This study analyzed PTC LNM by single-cell RNA sequencing (scRNA-seq) data and bulk RNA sequencing (RNA-seq) to find diagnostic markers and therapeutic targets.

METHODS

ScRNA-seq data were clustered and malignant cells were identified. Differentially expressed genes (DEGs) were identified in malignant cells of scRNA-seq and bulk RNA-seq, respectively. PTC LNM diagnostic model was constructed based on intersecting DEGs using glmnet package. Next, PTC samples from 66 patients were used to validate the two most significant genes in the diagnostic model, S100A2 and type 2 deiodinase (DIO2) by quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and immunohistochemical (IHC). Further, the inhibitory effect of DIO2 on PTC cells was verified by cell biology behavior, western blot, cell cycle analysis, 5-ethynyl-2'-deoxyuridine (EdU) assay, and xenograft tumors.

RESULTS

Heterogeneity of PTC LNM was demonstrated by Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis. A total of 19 differential genes were used to construct the diagnostic model. S100A2 and DIO2 differ significantly at the RNA (p < 0.01) and protein level in LNM patient tissues (p < 0.001). And differed in PTC tissues with different pathologic typing (p < 0.001). Further, EdU (p < 0.001) and cell biology behavior revealed that PTC cells overexpressed DIO2 had reduced proliferative capacity. Cell cycle proteins were reduced and cells are more likely to be stuck in G2/M phase (p < 0.001).

CONCLUSIONS

This study explored the heterogeneity of PTC LNM using scRNA-seq. By combining with bulk RNA-seq data, diagnostic markers were explored and the model was established. Clinical diagnostic efficacy of S100A2 and DIO2 was validated and the treatment potential of DIO2 was discovered.

Urine Biomarkers of Kidney Tubule Health and Risk of Incident CKD in Persons Without Diabetes: The ARIC, MESA, and REGARDS Studies

Rationale & Objective

Tubulointerstitial damage is a feature of early chronic kidney disease (CKD), but current clinical tests capture it poorly. Urine biomarkers of tubulointerstitial health may identify risk of CKD.

Study Design

Prospective cohort (Atherosclerosis Risk in Communities [ARIC]) and case-cohort (Multi-Ethnic Study of Atherosclerosis [MESA] and Reasons for Geographic and Racial Differences in Stroke [REGARDS]).

Setting & Participants

Adults with estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 and without diabetes in the ARIC, REGARDS, and MESA studies.

Exposures

Baseline urine monocyte chemoattractant protein-1 (MCP-1), alpha-1-microglobulin (α1m), kidney injury molecule-1, epidermal growth factor, and chitinase-3-like protein 1.

Outcome

Incident CKD or end-stage kidney disease.

Analytical Approach

Multivariable Cox proportional hazards regression for each cohort; meta-analysis of results from all 3 cohorts.

Results

872 ARIC participants (444 cases of incident CKD), 636 MESA participants (158 cases), and 924 REGARDS participants (488 cases) were sampled. Across cohorts, mean age ranged from 60 ± 10 to 63 ± 8 years, and baseline eGFR ranged from 88 ± 13 to 91 ± 14 mL/min/1.73 m2. In ARIC, higher concentrations of urine MCP-1, α1m, and kidney injury molecule-1 were associated with incident CKD. In MESA, higher concentration of urine MCP-1 and lower concentration of epidermal growth factor were each associated with incident CKD. In REGARDS, none of the biomarkers were associated with incident CKD. In meta-analysis of all 3 cohorts, each 2-fold increase α1m concentration was associated with incident CKD (HR, 1.19; 95% CI, 1.08-1.31).

Limitations

Observational design susceptible to confounding; competing risks during long follow-up period; meta-analysis limited to 3 cohorts.

Conclusions

In 3 combined cohorts of adults without prevalent CKD or diabetes, higher urine α1m concentration was independently associated with incident CKD. 4 biomarkers were associated with incident CKD in at least 1 of the cohorts when analyzed individually. Kidney tubule health markers might inform CKD risk independent of eGFR and albuminuria.

Mincle receptor in macrophage and neutrophil contributes to the unresolved inflammation during the transition from acute kidney injury to chronic kidney disease

Background

Recent studies have demonstrated a strong association between acute kidney injury (AKI) and chronic kidney disease (CKD), while the unresolved inflammation is believed to be a driving force for this chronic transition process. As a transmembrane pattern recognition receptor, Mincle (macrophage-inducible C-type lectin, Clec4e) was identified to participate in the early immune response after AKI. However, the impact of Mincle on the chronic transition of AKI remains largely unclear.

Methods

We performed single-cell RNA sequencing (scRNA-seq) with the unilateral ischemia-reperfusion (UIR) murine model of AKI at days 1, 3, 14 and 28 after injury. Potential effects and mechanism of Mincle on renal inflammation and fibrosis were further validated in vivo utilizing Mincle knockout mice.

Results

The dynamic expression of Mincle in macrophages and neutrophils throughout the transition from AKI to CKD was observed. For both cell types, Mincle expression was significantly up-regulated on day 1 following AKI, with a second rise observed on day 14. Notably, we identified distinct subclusters of Minclehigh neutrophils and Minclehigh macrophages that exhibited time-dependent influx with dual peaks characterized with remarkable pro-inflammatory and pro-fibrotic functions. Moreover, we identified that Minclehigh neutrophils represented an "aged" mature neutrophil subset derived from the "fresh" mature neutrophil cluster in kidney. Additionally, we observed a synergistic mechanism whereby Mincle-expressing macrophages and neutrophils sustained renal inflammation by tumor necrosis factor (TNF) production. Mincle-deficient mice exhibited reduced renal injury and fibrosis following AKI.

Conclusion

The present findings have unveiled combined persistence of Minclehigh neutrophils and macrophages during AKI-to-CKD transition, contributing to unresolved inflammation followed by fibrosis via TNF-α as a central pro-inflammatory cytokine. Targeting Mincle may offer a novel therapeutic strategy for preventing the transition from AKI to CKD.

LYC inhibits the AKT signaling pathway to activate autophagy and ameliorate TGFB-induced renal fibrosis

Renal fibrosis is a typical pathological change in chronic kidney disease (CKD). Epithelial-mesenchymal transition (EMT) is the predominant stage. Activation of macroautophagy/autophagy plays a crucial role in the process of EMT. Lycopene (LYC) is a highly antioxidant carotenoid with pharmacological effects such as anti-inflammation, anti-apoptosis and mediation of autophagy. In this study, we demonstrated the specific mechanism of LYC in activating mitophagy and improving renal fibrosis. The enrichment analysis results of GO and KEGG showed that LYC had high enrichment values with autophagy. In this study, we showed that LYC alleviated aristolochic acid I (AAI)-induced intracellular expression of PINK1, TGFB/TGF-β, p-SMAD2, p-SMAD3, and PRKN/Parkin, recruited expression of MAP1LC3/LC3-II and SQSTM1/p62, decreased mitochondrial membrane potential (MMP), and ameliorated renal fibrosis in mice. When we simultaneously intervened NRK52E cells using bafilomycin A1 (Baf-A1), AAI, and LYC, intracellular MAP1LC3-II and SQSTM1 expression was significantly increased. A similar result was seen in renal tissue and cells when treated in vitro and in vivo with CQ, AAI, and LYC, and the inhibitory effect of LYC on the AAI-activated SMAD2-SMAD3 signaling pathway was attenuated. Molecular docking simulation experiments showed that LYC stably bound to the AKT active site. After intervention of cells with AAI and GSK-690693, the expression of PINK1, PRKN, MAP1LC3-II, BECN1, p-SMAD2 and p-SMAD3 was increased, and the expression of SQSTM1 was decreased. However, SC79 inhibited autophagy and reversed the inhibitory effect of LYC on EMT. The results showed that LYC could inhibit the AKT signaling pathway to activate mitophagy and reduce renal fibrosis.Abbreviation: AA: aristolochic acid; ACTA2/α-SMA: actin alpha 2, smooth muscle, aorta; ACTB: actin beta; AKT/protein kinase B: thymoma viral proto-oncogene; BAF-A1: bafilomycin A1; BECN1: beclin 1, autophagy related; CCN2/CTGF: cellular communication network factor 2; CDH1/E-Cadherin: cadherin 1; CKD: chronic kidney disease; COL1: collagen, type I; COL3: collagen, type III; CQ: chloroquine; ECM: extracellular matrix; EMT: epithelial-mesenchymal transition; FN1: fibronectin 1; LYC: lycopene; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MMP: mitochondrial membrane potential; MTOR: mechanistic target of rapamycin kinase ; PI3K: phosphoinositide 3-kinase; PINK1: PTEN induced putative kinase 1; PRKN/Parkin: parkin RBR E3 ubiquitin protein ligase; PPI: protein-protein interaction; SMAD2: SMAD family member 2; SMAD3: SMAD family member 3; SQSTM1/p62: sequestosome 1; TGFB/TGFβ: transforming growth factor, beta; VIM: vimentin.

The Aftermath of COVID-19: Exploring the Long-Term Effects on Organ Systems

BACKGROUND

Post-acute sequelae of SARS-CoV-2 infection (PASC) is a complicated disease that affects millions of people all over the world. Previous studies have shown that PASC impacts 10% of SARS-CoV-2 infected patients of which 50-70% are hospitalised. It has also been shown that 10-12% of those vaccinated against COVID-19 were affected by PASC and its complications. The severity and the later development of PASC symptoms are positively associated with the early intensity of the infection.

RESULTS

The generated health complications caused by PASC involve a vast variety of organ systems. Patients affected by PASC have been diagnosed with neuropsychiatric and neurological symptoms. The cardiovascular system also has been involved and several diseases such as myocarditis, pericarditis, and coronary artery diseases were reported. Chronic hematological problems such as thrombotic endothelialitis and hypercoagulability were described as conditions that could increase the risk of clotting disorders and coagulopathy in PASC patients. Chest pain, breathlessness, and cough in PASC patients were associated with the respiratory system in long-COVID causing respiratory distress syndrome. The observed immune complications were notable, involving several diseases. The renal system also was impacted, which resulted in raising the risk of diseases such as thrombotic issues, fibrosis, and sepsis. Endocrine gland malfunction can lead to diabetes, thyroiditis, and male infertility. Symptoms such as diarrhea, nausea, loss of appetite, and taste were also among reported observations due to several gastrointestinal disorders. Skin abnormalities might be an indication of infection and long-term implications such as persistent cutaneous complaints linked to PASC.

CONCLUSIONS

Long-COVID is a multidimensional syndrome with considerable public health implications, affecting several physiological systems and demanding thorough medical therapy, and more study to address its underlying causes and long-term effects is needed.

Recently Updated Role of Chitinase 3-like 1 on Various Cell Types as a Major Influencer of Chronic Inflammation

Chitinase 3-like 1 (also known as CHI3L1 or YKL-40) is a mammalian chitinase that has no enzymatic activity, but has the ability to bind to chitin, the polymer of N-acetylglucosamine (GlcNAc). Chitin is a component of fungi, crustaceans, arthropods including insects and mites, and parasites, but it is completely absent from mammals, including humans and mice. In general, chitin-containing organisms produce mammalian chitinases, such as CHI3L1, to protect the body from exogenous pathogens as well as hostile environments, and it was thought that it had a similar effect in mammals. However, recent studies have revealed that CHI3L1 plays a pathophysiological role by inducing anti-apoptotic activity in epithelial cells and macrophages. Under chronic inflammatory conditions such as inflammatory bowel disease and chronic obstructive pulmonary disease, many groups already confirmed that the expression of CHI3L1 is significantly induced on the apical side of epithelial cells, and activates many downstream pathways involved in inflammation and carcinogenesis. In this review article, we summarize the expression of CHI3L1 under chronic inflammatory conditions in various disorders and discuss the potential roles of CHI3L1 in those disorders on various cell types.

The immunoregulatory roles of non-haematopoietic cells in the kidney

The deposition of immune complexes, activation of complement and infiltration of the kidney by cells of the adaptive and innate immune systems have long been considered responsible for the induction of kidney damage in autoimmune, alloimmune and other inflammatory kidney diseases. However, emerging findings have highlighted the contribution of resident immune cells and of immune molecules expressed by kidney-resident parenchymal cells to disease processes. Several types of kidney parenchymal cells seem to express a variety of immune molecules with a distinct topographic distribution, which may reflect the exposure of these cells to different pathogenic threats or microenvironments. A growing body of literature suggests that these cells can stimulate the infiltration of immune cells that provide protection against infections or contribute to inflammation - a process that is also regulated by draining kidney lymph nodes. Moreover, components of the immune system, such as autoantibodies, cytokines and immune cells, can influence the metabolic profile of kidney parenchymal cells in the kidney, highlighting the importance of crosstalk in pathogenic processes. The development of targeted nanomedicine approaches that modulate the immune response or control inflammation and damage directly within the kidney has the potential to eliminate the need for systemically acting drugs.

Discovery of 2,8-dihydroxyadenine in HUA patients with uroliths and biomarkers for its associated nephropathy

Currently, it is acknowledged that gout is caused by uric acid (UA). However, some studies have revealed no correlation between gout and UA levels, and growing evidence suggests that 2,8-dihydroxyadenine (2,8-DHA), whose structural formula is similar to UA but is less soluble, may induce gout. Hence, we hypothesized that uroliths from hyperuricemia (HUA) patients, which is closely associated with gout, may contain 2,8-DHA. In this study, 2,8-DHA in uroliths and serum of HUA patients were determined using HPLC. Moreover, bioinformatics was used to investigate the pathogenic mechanisms of 2,8-DHA nephropathy. Subsequently, a mouse model of 2,8-DHA nephropathy established by the gavage administration of adenine, as well as a model of injured HK-2 cells induced by 2,8-DHA were used to explore the pathogenesis of 2,8-DHA nephropathy. Interestingly, 2,8-DHA could readily deposit in the cortex of the renal tubules, and was found in the majority of these HUA patients. Additionally, the differentially expressed genes between 2,8-DHA nephropathy mice and control mice were found to be involved in inflammatory reactions. Importantly, CCL2 and IL-1β genes had the maximum degree, closeness, and betweenness centrality scores. The expressions of CCL2 and IL-1β genes were significantly increased in the serum of 24 HUA patients with uroliths, indicating that they may be significant factors for 2,8-DHA nephropathy. Further analysis illustrated that oxidative damage and inflammation were the crucial processes of 2,8-DHA renal injury, and CCL2 and IL-1β genes were verified to be essential biomarkers for 2,8-DHA nephropathy. These findings revealed further insights into 2,8-DHA nephropathy, and provided new ideas for its diagnosis and treatment.

Associations of urinary fetuin-A with histopathology and kidney events in biopsy-proven kidney disease

Background

Fetuin-A is implicated in the pathogenesis of vascular calcification in chronic kidney disease (CKD); however, the relationship between fetuin-A, histopathologic lesions and long-term kidney outcomes in patients with various types of kidney disease remains unclear.

Methods

We measured urinary fetuin-A levels in 335 individuals undergoing clinically indicated native kidney biopsy. The expressions of fetuin-A mRNA and protein in the kidney were assessed using RNA sequencing and immunohistochemistry. The association of urinary fetuin-A with histopathologic lesions and major adverse kidney events (MAKE), defined as a decline in estimated glomerular filtration rate (eGFR) of at least 40%, kidney failure or death, was analyzed.

Results

Urinary fetuin-A levels showed a positive correlation with albuminuria (rs = 0.67, P < .001) and a negative correlation with eGFR (rs = -0.46, P < .001). After multivariate adjustment, higher urinary fetuin-A levels were associated with glomerular inflammation, mesangial expansion, interstitial fibrosis and tubular atrophy, and arteriolar sclerosis. Using a 1 transcript per million gene expression cutoff, we found kidney fetuin-A mRNA levels below the threshold in both individuals with normal kidney function and those with CKD. Additionally, immunohistochemistry revealed reduced fetuin-A staining in tubular cells of CKD patients compared with normal controls. During a median 21-month follow-up, 115 patients experienced MAKE, and Cox regression analysis confirmed a significant association between elevated urinary fetuin-A and MAKE. This association remained significant after adjusting for potential confounding factors.

Conclusion

Urinary fetuin-A is associated with chronic histological damage and adverse clinical outcomes across a spectrum of biopsy-proven kidney diseases.

Fibrosis in Chronic Kidney Disease: Pathophysiology and Therapeutic Targets

Chronic kidney disease (CKD) is a slowly progressive condition characterized by decreased kidney function, tubular injury, oxidative stress, and inflammation. CKD is a leading global health burden that is asymptomatic in early stages but can ultimately cause kidney failure. Its etiology is complex and involves dysregulated signaling pathways that lead to fibrosis. Transforming growth factor (TGF)-β is a central mediator in promoting transdifferentiation of polarized renal tubular epithelial cells into mesenchymal cells, resulting in irreversible kidney injury. While current therapies are limited, the search for more effective diagnostic and treatment modalities is intensive. Although biopsy with histology is the most accurate method of diagnosis and staging, imaging techniques such as diffusion-weighted magnetic resonance imaging and shear wave elastography ultrasound are less invasive ways to stage fibrosis. Current therapies such as renin-angiotensin blockers, mineralocorticoid receptor antagonists, and sodium/glucose cotransporter 2 inhibitors aim to delay progression. Newer antifibrotic agents that suppress the downstream inflammatory mediators involved in the fibrotic process are in clinical trials, and potential therapeutic targets that interfere with TGF-β signaling are being explored. Small interfering RNAs and stem cell-based therapeutics are also being evaluated. Further research and clinical studies are necessary in order to avoid dialysis and kidney transplantation.

Association of daytime napping with incidence of chronic kidney disease and end-stage kidney disease: A prospective observational study

BACKGROUND AND AIMS

Few studies have examined the relationship between daytime napping and risk of kidney diseases. We aimed to investigate the association of daytime napping with the incidence of chronic kidney disease (CKD) and end-stage kidney disease (ESKD). We also examined whether sleep duration modified the association of nap with CKD or ESKD.

METHODS

We recruited 460,571 European middle- to older-aged adults without prior CKD or ESKD between March 13, 2006, and October 1, 2010, in the UK Biobank. Sleep behavior data were obtained through questionnaires administered during recruitment. The analysis of the relationship between napping and the occurrence of CKD and ESKD utilized Cox proportional hazards regression models. The modification role of sleep duration on the effect of nap on CKD and ESKD was also examined.

RESULTS

After a mean follow-up of 11.1 (standard deviation 2.2) years, we observed 28,330 incident CKD cases and 927 ESKD cases. The daytime napping was associated with incident CKD (P for trend = .004). After fully adjusted, when compared with participants who did not take nap, those in sometimes and usually nap groups had higher risk of CKD. Nevertheless, the available evidence did not support a link between daytime napping and ESKD (P for trend = .06). Simultaneously, there was insufficient evidence suggesting that sleeping duration modified the association of daytime napping with incident CKD or ESKD.

CONCLUSION

Daytime napping was associated with an increased risk of CKD. However, the absence of conclusive evidence did not indicate a connection between daytime napping and ESKD.

New insights into the role of immunity and inflammation in diabetic kidney disease in the omics era

Diabetic kidney disease (DKD) is becoming the leading cause of chronic kidney disease, especially in the industrialized world. Despite mounting evidence has demonstrated that immunity and inflammation are highly involved in the pathogenesis and progression of DKD, the underlying mechanisms remain incompletely understood. Substantial molecules, signaling pathways, and cell types participate in DKD inflammation, by integrating into a complex regulatory network. Most of the studies have focused on individual components, without presenting their importance in the global or system-based processes, which largely hinders clinical translation. Besides, conventional technologies failed to monitor the different behaviors of resident renal cells and immune cells, making it difficult to understand their contributions to inflammation in DKD. Recently, the advancement of omics technologies including genomics, epigenomics, transcriptomics, proteomics, and metabolomics has revolutionized biomedical research, which allows an unbiased global analysis of changes in DNA, RNA, proteins, and metabolites in disease settings, even at single-cell and spatial resolutions. They help us to identify critical regulators of inflammation processes and provide an overview of cell heterogeneity in DKD. This review aims to summarize the application of multiple omics in the field of DKD and emphasize the latest evidence on the interplay of inflammation and DKD revealed by these technologies, which will provide new insights into the role of inflammation in the pathogenesis of DKD and lead to the development of novel therapeutic approaches and diagnostic biomarkers.

Urinary Biomarkers and Kidney Injury in VA NEPHRON-D: Phenotyping Acute Kidney Injury in Clinical Trials

RATIONALE & OBJECTIVE

Urinary biomarkers of injury, inflammation, and repair may help phenotype acute kidney injury (AKI) observed in clinical trials. We evaluated the differences in biomarkers between participants randomized to monotherapy or to combination renin-angiotensin-aldosterone system (RAAS) blockade in VA NEPHRON-D, where an increased proportion of observed AKI was acknowledged in the combination arm.

STUDY DESIGN

Longitudinal analysis.

SETTING & PARTICIPANTS

A substudy of the VA NEPHRON-D trial.

PREDICTOR

Primary exposure was the treatment arm (combination [RAAS inhibitor] vs monotherapy). AKI is used as a stratifying variable.

OUTCOME

Urinary biomarkers, including albumin, EGF (epidermal growth factor), MCP-1 (monocyte chemoattractant protein-1), YKL-40 (chitinase 3-like protein 1), and KIM-1 (kidney injury molecule-1).

ANALYTICAL APPROACH

Biomarkers measured at baseline and at 12 months in trial participants were compared between treatment groups and by AKI. AKI events occurring during hospitalization were predefined safety end points in the original trial. The results were included in a meta-analysis with other large chronic kidney disease trials to assess global trends in biomarker changes.

RESULTS

In 707 participants followed for a median of 2.2 years, AKI incidence was higher in the combination (20.7%) versus the monotherapy group (12.7%; relative risk [RR], 1.64 [95% CI, 1.16-2.30]). Compared with the monotherapy arm, in the combination arm the urine biomarkers at 12 months were either unchanged (MCP-1: RR, -3% [95% CI, -13% to 9%], Padj=0.8; KIM-1: RR, -10% [95% CI, -20% to 1%], Padj=0.2; EGF, RR-7% [95% CI, -12% to-1%], Padj=0.08) or lower (albuminuria: RR, -24% [95% CI, -37% to-8%], Padj=0.02; YKL: RR, -40% to-44% [95% CI, -58% to-25%], Padj<0.001). Pooled meta-analysis demonstrated reduced albuminuria in the intervention arm across 3 trials and similar trajectories in other biomarkers.

LIMITATIONS

Biomarker measurement was limited to 2 time points independent of AKI events.

CONCLUSIONS

Despite the increased risk of serum creatinine-defined AKI, combination RAAS inhibitor therapy was associated with unchanged or decreased urinary biomarkers at 12 months. This suggests a possible role for kidney biomarkers to further characterize kidney injury in clinical trials.

PLAIN-LANGUAGE SUMMARY

The VA NEPHRON-D trial investigated inhibition of the renin-angiotensin-aldosterone system (RAAS) hormonal axis on kidney outcomes in a large population of diabetic chronic kidney disease patients. The trial was stopped early due to increased events of serum creatinine-defined acute kidney injury in the combination therapy arm. Urine biomarkers can serve as an adjunct to serum creatinine in identifying kidney injury. We found that urinary biomarkers in the combination therapy group were not associated with a pattern of harm and damage to the kidney, despite the increased number of kidney injury events in that group. This suggests that serum creatinine alone may be insufficient for defining kidney injury and supports further exploration of how other biomarkers might improve identification of kidney injury in clinical trials.

The occurrence and development mechanisms of esophageal stricture: state of the art review

BACKGROUND

Esophageal strictures significantly impair patient quality of life and present a therapeutic challenge, particularly due to the high recurrence post-ESD/EMR. Current treatments manage symptoms rather than addressing the disease's etiology. This review concentrates on the mechanisms of esophageal stricture formation and recurrence, seeking to highlight areas for potential therapeutic intervention.

METHODS

A literature search was conducted through PUBMED using search terms: esophageal stricture, mucosal resection, submucosal dissection. Relevant articles were identified through manual review with reference lists reviewed for additional articles.

RESULTS

Preclinical studies and data from animal studies suggest that the mechanisms that may lead to esophageal stricture include overdifferentiation of fibroblasts, inflammatory response that is not healed in time, impaired epithelial barrier function, and multimethod factors leading to it. Dysfunction of the epithelial barrier may be the initiating mechanism for esophageal stricture. Achieving perfect in-epithelialization by tissue-engineered fabrication of cell patches has been shown to be effective in the treatment and prevention of esophageal strictures.

CONCLUSION

The development of esophageal stricture involves three stages: structural damage to the esophageal epithelial barrier (EEB), chronic inflammation, and severe fibrosis, in which dysfunction or damage to the EEB is the initiating mechanism leading to esophageal stricture. Re-epithelialization is essential for the treatment and prevention of esophageal stricture. This information will help clinicians or scientists to develop effective techniques to treat esophageal stricture in the future.

Angiopoietin as a Novel Prognostic Marker in Kidney Disease

INTRODUCTION

Renal injury is among the leading causes of morbidity and mortality; however, there are no reliable indicators for determining the likelihood of developing chronic kidney disease (CKD), CKD progression, or AKI events. Vascular growth factors called angiopoietins have a role in endothelial function, vascular remodeling, tissue stabilization, and inflammation and have been implicated as prognostic and predictive markers in AKI.

METHODS

Although the exact mechanism of the relationship between kidney injury and angiopoietins is unknown, this review demonstrates that AKI patients have higher angiopoietin-2 levels and that higher angiopoietin-1 to angiopoietin-2 ratio may potentially be linked with a reduced risk of the CKD progression.

RESULTS

This review therefore emphasizes the importance of angiopoietin-2 and proposes that it could be an important predictor of AKI in clinical settings.

CONCLUSION

There is a need for further large-scale randomized clinical trials in order to have a better understanding of the significance of angiopoietin-2 and for the determination of its potential clinical implications.

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.

PHENOTYPING REPAIR AFTER ACUTE KIDNEY INJURY: PRECISION MEDICINE TO CLINICAL TRIALS

Acute kidney injury (AKI) is common during hospitalization and is associated with long-term risk of readmissions and chronic kidney disease (CKD). Preclinical studies and novel urine biomarkers have demonstrated that subclinical inflammation and repair continue for several months after AKI. We conducted three clinical and translational studies to alleviate long-term sequelae after AKI. First, we assessed repair in deceased donor kidneys which can assist with organ allocation and reduce discard. In an ongoing study, organ procurement organizations are measuring repair biomarkers via lateral flow devices to assess organ quality and adding it to their workflow. Second, we performed research biopsies during AKI to interrogate kidney tissue with novel transcriptomic and proteomic techniques to advance therapeutic development. Third, we initiated pragmatic clinical trials to reduce readmissions after an episode of AKI by providing nurse navigator and pharmacist support to optimize blood pressure, fluid, and medication management.

Associations of Biomarkers of Tubular Injury and Inflammation with Biopsy Features in Type 1 Diabetes

BACKGROUND

Whether biomarkers of tubular injury and inflammation indicate subclinical structural kidney pathology early in type 1 diabetes remains unknown.

METHODS

We investigated associations of biomarkers of tubular injury and inflammation with kidney structural features in 244 adults with type 1 diabetes from the Renin-Angiotensin System Study, a randomized, placebo-controlled trial testing effects of enalapril or losartan on changes in glomerular, tubulointerstitial, and vascular parameters from baseline to 5-year kidney biopsies. Biosamples at biopsy were assessed for kidney injury molecule 1 (KIM-1), soluble TNF receptor 1 (sTNFR1), arginine-to-citrulline ratio in plasma, and uromodulin and epidermal growth factor (EGF) in urine. We examined cross-sectional correlations between biomarkers and biopsy features and baseline biomarker associations with 5-year changes in biopsy features.

RESULTS

Participants' mean age was 30 years (SD 10) and diabetes duration 11 years (SD 5); 53% were women. The mean GFR measured by iohexol disappearance was 128 ml/min per 1.73 m 2 (SD 19) and median urinary albumin excretion was 5 μ g/min (interquartile range, 3-8). KIM-1 was associated with most biopsy features: higher mesangial fractional volume (0.5% [95% confidence interval (CI), 0.1 to 0.9] greater per SD KIM-1), glomerular basement membrane (GBM) width (14.2 nm [95% CI, 6.5 to 22.0] thicker), cortical interstitial fractional volume (1.1% [95% CI, 0.6 to 1.6] greater), fractional volume of cortical atrophic tubules (0.6% [95% CI, 0.2 to 0.9] greater), and arteriolar hyalinosis index (0.03 [95% CI, 0.1 to 0.05] higher). sTNFR1 was associated with higher mesangial fractional volume (0.9% [95% CI, 0.5 to 1.3] greater) and GBM width (12.5 nm [95% CI, 4.5 to 20.5] thicker) and lower GBM surface density (0.003 μ m 2 / μ m 3 [95% CI, 0.005 to 0.001] lesser). EGF and arginine-to-citrulline ratio correlated with severity of glomerular and tubulointerstitial features. Baseline sTNFR1, uromodulin, and EGF concentrations were associated with 5-year glomerular and tubulointerstitial feature progression.

CONCLUSIONS

Biomarkers of tubular injury and inflammation were associated with kidney structural parameters in early type 1 diabetes and may be indicators of kidney disease risk.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Renin Angiotensin System Study (RASS/B-RASS), NCT00143949.

PODCAST

This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/CJASN/2023_11_17_CJN0000000000000333.mp3.

Analysis of the human kidney transcriptome and plasma proteome identifies markers of proximal tubule maladaptation to injury

Acute kidney injury (AKI) is a major risk factor for long-term adverse outcomes, including chronic kidney disease. In mouse models of AKI, maladaptive repair of the injured proximal tubule (PT) prevents complete tissue recovery. However, evidence for PT maladaptation and its etiological relationship with complications of AKI is lacking in humans. We performed single-nucleus RNA sequencing of 120,985 nuclei in kidneys from 17 participants with AKI and seven healthy controls from the Kidney Precision Medicine Project. Maladaptive PT cells, which exhibited transcriptomic features of dedifferentiation and enrichment in pro-inflammatory and profibrotic pathways, were present in participants with AKI of diverse etiologies. To develop plasma markers of PT maladaptation, we analyzed the plasma proteome in two independent cohorts of patients undergoing cardiac surgery and a cohort of marathon runners, linked it to the transcriptomic signatures associated with maladaptive PT, and identified nine proteins whose genes were specifically up- or down-regulated by maladaptive PT. After cardiac surgery, both cohorts of patients had increased transforming growth factor-β2 (TGFB2), collagen type XXIII-α1 (COL23A1), and X-linked neuroligin 4 (NLGN4X) and had decreased plasminogen (PLG), ectonucleotide pyrophosphatase/phosphodiesterase 6 (ENPP6), and protein C (PROC). Similar changes were observed in marathon runners with exercise-associated kidney injury. Postoperative changes in these markers were associated with AKI progression in adults after cardiac surgery and post-AKI kidney atrophy in mouse models of ischemia-reperfusion injury and toxic injury. Our results demonstrate the feasibility of a multiomics approach to discovering noninvasive markers and associating PT maladaptation with adverse clinical outcomes.

YKL-40 promotes proliferation and invasion of HTR-8/SVneo cells by activating akt/MMP9 signalling in placenta accreta spectrum disorders

YKL-40 is a secreted glycoprotein that can promote invasion, angiogenesis and inhibit apoptosis, and was highly expressed in a variety of tumours. In this paper, we investigated the impacts of YKL-40 on proliferation and invasion in HTR-8/SVneo cells during placenta accreta spectrum disorders (PAS) development. The levels of YKL-40 protein in late-pregnant placental tissue were detected using immunohistochemistry and Western blotting, and gene expression using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The proliferation, migration, invasion and apoptosis abilities of HTR-8/SVneo cells were detected by cell counting kit-8 (CCK-8), Transwell, scratch assay, and flow cytometry, respectively. Our current results showed that YKL-40 was significantly increased in the PAS group compared to the normal control group (P < 0.01). Biological function experiments showed that YKL-40 significantly promoted the proliferation, migration and invasion of HTR-8/SVneo cells, and inhibited cell apoptosis. Knockdown of YKL-40 inhibited the activation of Akt/MMP9 signalling in trophoblast cells. These data suggested that YKL-40 might be involved in the progression of PAS, which may be attributed to the regulation of Akt/MMP9 signalling pathway.

Emerging Preventive Strategies in Chronic Kidney Disease: Recent Evidence and Gaps in Knowledge

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is increasingly prevalent worldwide and is associated with increased cardiovascular risk. New therapeutic options to slow CKD progression and reduce cardiovascular morbidity and mortality have recently emerged. This review highlights recent evidence and gaps in knowledge in emerging CKD preventive strategies.

RECENT FINDINGS

EMPA-Kidney trial found that empagliflozin, a sodium-glucose co-transporter 2 inhibitor (SGLT2i) led to 28% lower risk of progression of kidney disease or death from cardiovascular causes, compared to placebo. This reinforced the previous findings from DAPA-CKD and CREDENCE trials and led to inclusion of SGLT2i as the cornerstone of CKD preventive therapy in both diabetic and non-diabetic CKD. Finerenone, a selective nonsteroidal mineralocorticoid receptor antagonist, slowed diabetic kidney disease progression by 23% compared to placebo in a pool analysis of FIDELIO-DKD and FIGARO-DKD trials. Non-pharmacological interventions, including low protein diet, and early CKD detection and risk stratification strategies based on novel biomarkers have also gained momentum. Ongoing efforts to explore the wealth of molecular mechanisms in CKD, added to integrative omics modeling are well posed to lead to novel therapeutic targets in kidney care. While breakthrough pharmacological interventions continue to improve outcomes in CKD, the heterogeneity of kidney diseases warrants additional investigation. Further research into specific kidney disease mechanisms will facilitate the identification of patient populations most likely to benefit from targeted interventions.

Inflammation and renal function decline in chronic coronary syndrome: a prospective multicenter cohort study

BACKGROUND

Renal function decline is a frequently encountered complication in patients with chronic coronary syndrome. Aside from traditional cardiovascular risk factors, the inflammatory burden emerged as the novel phenotype that compromised renal prognosis in such population.

METHODS

A cohort with chronic coronary syndrome was enrolled to investigate the association between inflammatory status and renal dysfunction. Levels of inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP), tumour necrosis factor-α (TNF-α), adiponectin, matrix metalloproteinase-9, interleukin-6, lipoprotein-associated phospholipase A2, were assessed. Renal event was defined as > 25% decline in estimated glomerular filtration rate (eGFR). Inflammatory scores were calculated based on the aggregate of hs-CRP, TNF-α, and adiponectin levels.

RESULTS

Among the 850 enrolled subjects, 145 patients sustained a renal event during an averaged 3.5 years follow-up. Multivariate analysis with Cox regression suggested elevations in hs-CRP, TNF-α, and adiponectin levels were independent risk factors for the occurrence of a renal event. Whereas, Kaplan-Meier curve illustrated significant correlation between high TNF-α (P = 0.005), adiponectin (P < 0.001), but not hs-CRP (P = 0.092), and eGFR decline. The aggregative effect of these biomarkers was also distinctly correlated with renal events (score 2: P = 0.042; score 3: P < 0.001).

CONCLUSIONS

Inflammatory burden was associated with eGFR decline in patients with chronic coronary syndrome.

Plasma Biomarkers and Incident CKD Among Individuals Without Diabetes

Rationale & Objective

Biomarkers of kidney disease progression have been identified in individuals with diabetes and underlying chronic kidney disease (CKD). Whether or not these markers are associated with the development of CKD in a general population without diabetes or CKD is not well established.

Study Design

Prospective observational cohort.

Setting & Participants

In the Atherosclerosis Risk in Communities) study, 948 participants were studied.

Exposures

The baseline plasma biomarkers of kidney injury molecule-1 (KIM-1), monocyte chemoattractant protein-1 (MCP-1), soluble urokinase plasminogen activator receptor (suPAR), tumor necrosis factor receptor 1 (TNFR-1), tumor necrosis factor receptor 2 (TNFR-2), and human cartilage glycoprotein-39 (YKL-40) measured in 1996-1998.

Outcome

Incident CKD after 15 years of follow-up defined as ≥40% estimated glomerular filtration rate decline to <60 mL/min/1.73 m2 or dialysis dependence through United States Renal Data System linkage.

Analytical Approach

Logistic regression and C statistics.

Results

There were 523 cases of incident CKD. Compared with a random sample of 425 controls, there were greater odds of incident CKD per 2-fold higher concentration of KIM-1 (OR, 1.49; 95% CI, 1.25-1.78), suPAR (OR, 2.57; 95% CI, 1.74-3.84), TNFR-1 (OR, 2.20; 95% CI, 1.58-3.09), TNFR-2 (OR, 2.03; 95% CI, 1.37-3.04). After adjustment for all biomarkers, KIM-1 (OR, 1.42; 95% CI, 1.19-1.71), and suPAR (OR, 1.86; 95% CI, 1.18-2.92) remained associated with incident CKD. Compared with traditional risk factors, the addition of all 6 biomarkers improved the C statistic from 0.695-0.731 (P < 0.01) and using the observed risk of 12% for incident CKD, the predicted risk gradient changed from 5%-40% (for the 1st-5th quintile) to 4%-44%.

Limitations

Biomarkers and creatinine were measured at one time point.

Conclusions

Higher levels of KIM-1, suPAR, TNFR-1, and TNFR-2 were associated with higher odds of incident CKD among individuals without diabetes.

Plain-Language Summary

For people with diabetes or kidney disease, several biomarkers have been shown to be associated with worsening kidney disease. Whether these biomarkers have prognostic significance in people without diabetes or kidney disease is less studied. Using the Atherosclerosis Risk in Communities study, we followed individuals without diabetes or kidney disease for an average of 15 years after biomarker measurement to see if these biomarkers were associated with the development of kidney disease. We found that elevated levels of KIM-1, suPAR, TNFR-1, and TNFR-2 were associated with the development of kidney disease. These biomarkers may help identify individuals who would benefit from interventions to prevent the development of kidney disease.