Single-cell RNA sequencing reveals the transcriptomic landscape of kidneys in patients with ischemic acute kidney injury / 中华医学杂志(英文版)

BACKGROUND@#Ischemic acute kidney injury (AKI) is a common syndrome associated with considerable mortality and healthcare costs. Up to now, the underlying pathogenesis of ischemic AKI remains incompletely understood, and specific strategies for early diagnosis and treatment of ischemic AKI are still lacking. Here, this study aimed to define the transcriptomic landscape of AKI patients through single-cell RNA sequencing (scRNA-seq) analysis in kidneys.@*METHODS@#In this study, scRNA-seq technology was applied to kidneys from two ischemic AKI patients, and three human public scRNA-seq datasets were collected as controls. Differentially expressed genes (DEGs) and cell clusters of kidneys were determined. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, as well as the ligand-receptor interaction between cells, were performed. We also validated several DEGs expression in kidneys from human ischemic AKI and ischemia/reperfusion (I/R) injury induced AKI mice through immunohistochemistry staining.@*RESULTS@#15 distinct cell clusters were determined in kidney from subjects of ischemic AKI and control. The injured proximal tubules (PT) displayed a proapoptotic and proinflammatory phenotype. PT cells of ischemic AKI had up-regulation of novel pro-apoptotic genes including USP47 , RASSF4 , EBAG9 , IER3 , SASH1 , SEPTIN7 , and NUB1 , which have not been reported in ischemic AKI previously. Several hub genes were validated in kidneys from human AKI and renal I/R injury mice, respectively. Furthermore, PT highly expressed DEGs enriched in endoplasmic reticulum stress, autophagy, and retinoic acid-inducible gene I (RIG-I) signaling. DEGs overexpressed in other tubular cells were primarily enriched in nucleotide-binding and oligomerization domain (NOD)-like receptor signaling, estrogen signaling, interleukin (IL)-12 signaling, and IL-17 signaling. Overexpressed genes in kidney-resident immune cells including macrophages, natural killer T (NKT) cells, monocytes, and dendritic cells were associated with leukocyte activation, chemotaxis, cell adhesion, and complement activation. In addition, the ligand-receptor interactions analysis revealed prominent communications between macrophages and monocytes with other cells in the process of ischemic AKI.@*CONCLUSION@#Together, this study reveals distinct cell-specific transcriptomic atlas of kidney in ischemic AKI patients, altered signaling pathways, and potential cell-cell crosstalk in the development of AKI. These data reveal new insights into the pathogenesis and potential therapeutic strategies in ischemic AKI.

Elevated levels of platelet-to-lymphocyte ratio may predict the reduced risk of MPO-ANCA associated vasculitis in Chinese patients with end stage of renal disease / 中南大学学报(医学版)

Objective: Platelet-to-lymphocyte ratio (PLR) has recently been investigated as a new inflammatory marker in many inflammatory diseases, including systemic lupus erythematosus and immunoglobulin A vasculitis. However, there were very few reports regarding the clinical role of PLR in patients with anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis. This study was thus undertaken to investigate the relationship between inflammatory response and disease activity in Chinese patients with myeloperoxidase-anti-neutrophil cytoplasmic antibody (MPO-ANCA) associated vasculitis. Furthermore, we evaluated whether PLR predicts the progression of end stage of renal disease (ESRD) and all-cause mortality.Methods:The clinical, laboratory and pathological data, and the outcomes of MPO-ANCA associated vasculitis patients were collected. The Spearman correlation coefficient was computed to examine the association between 2 continuous variables. Cox regression analysis was used to estimate the association between PLR and ESRD or all-cause mortality. Results:A total of 190 consecutive patients with MPO-ANCA associated vasculitis were included in this study. Baseline PLR was positively correlated with CRP (r=0.333, P<0.001) and ESR (r=0.218, P=0.003). PLR had no obvious correlation with Birmingham Vasculitis Activity Score (BVAS). Patients having PLR≥330 exhibited better cumulative renal survival rates than those having PLR<330 (P=0.017). However, there was no significant difference in the cumulative patient survival rates between patients with PLR≥330 and those with PLR<330 at diagnosis (P>0.05). In multivariate analysis, PLR is associated with the decreased risk of ESRD (P=0.038, HR=0.518, 95％CI 0.278 to 0.963). We did not find an association between PLR with all-cause mortality using multivariate analysis (HR=1.081, 95％CI 0.591 to 1.976, P=0.801).Conclusion: PLR is positively correlated with CRP and ESR. Furthermore, PLR may independently predict the risk of ESRD.

High levels of platelet-to-lymphocyte ratio may predict reduced risk of end stage of renal disease in Chinese patients with MPO-ANCA associated vasculitis / 中南大学学报(医学版)

OBJECTIVES@#Platelet-to-lymphocyte ratio (PLR) has recently been investigated as a new inflammatory marker in many inflammatory diseases, including systemic lupus erythematosus and immunoglobulin A vasculitis. However, there were very few reports regarding the clinical role of PLR in patients with anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis. This study was thus undertaken to investigate the relationship between inflammatory response and disease activity in Chinese patients with myeloperoxidase-anti-neutrophil cytoplasmic antibody (MPO-ANCA) associated vasculitis. Furthermore, we evaluated whether PLR predicts the progression of end stage of renal disease (ESRD) and all-cause mortality.@*METHODS@#The clinical, laboratory and pathological data, and the outcomes of MPO-ANCA associated vasculitis patients were collected. The Spearman correlation coefficient was computed to examine the association between 2 continuous variables. Cox regression analysis was used to estimate the association between PLR and ESRD or all-cause mortality.@*RESULTS@#A total of 190 consecutive patients with MPO-ANCA associated vasculitis were included in this study. Baseline PLR was positively correlated with CRP (r=0.333, P<0.001) and ESR (r=0.218, P=0.003). PLR had no obvious correlation with Birmingham Vasculitis Activity Score (BVAS). Patients having PLR≥330 exhibited better cumulative renal survival rates than those having PLR<330 (P=0.017). However, there was no significant difference in the cumulative patient survival rates between patients with PLR≥330 and those with PLR<330 at diagnosis (P>0.05). In multivariate analysis, PLR is associated with the decreased risk of ESRD (P=0.038, HR=0.518, 95% CI 0.278 to 0.963). We did not find an association between PLR with all-cause mortality using multivariate analysis (HR=1.081, 95% CI 0.591 to 1.976, P=0.801).@*CONCLUSIONS@#PLR is positively correlated with CRP and ESR. Furthermore, PLR may independently predict the risk of ESRD.

To investigate the relationship between P15INK4B gene promoter methylation degree and different types of MDS and prognosis / 中国医师杂志

Objective To determine the methylation level of P15INK4B gene promoter in different types of myelodysplastic syndromes (MDS) and its correlation with its prognosis.Methods Methylation frequency of the P15INK4B gene promoter in 44 cases of MDS were determined by methylation-specific polymerase chain reaction (PCR) and pyrosequencing,and its correlation with clinical classification and characteristics of MDS were statistically analyzed.Results Frequency of P15INK4B gene promoter methylation in myelodysplastic syndromes-refractory anemia with excess blasts Ⅱ (MDS-RAEB Ⅱ) patients was (46.89 ± 15.41) ％,significandy higher than that in other types of MDS (P ＜ 0.05),but no difference in promoter methylation frequency was detected among the other types of MDS (P ＞ 0.05) ; frequency of P15INK4B gene promoter methylation was found to be correlated with decline in platelet upon diagnosis (t =9.02,P ＜ 0.01),but showed no significant correlation with drop of hemoglobin or leukopenia (P ＞0.05).As for the correlation between P15INK4B gene promoter methylation and MDS risk stratification,no significant difference was detected between the low-risk and very low-risk groups (P ＞ 0.05),but significant differences were detected among the medium-risk,high-risk,and very high-risk groups (P ＜ 0.05).In addition,frequency of P15INK4B gene promoter methylation was (49.21 ± 8.78)％ in MDS patients that developed leukemia in the following two year,significantly higher than that in MDS patients who didn't (19.64 ± 6.24) ％ (P ＜ 0.05).Conclusions P15INK4B gene promoter methylation frequency is a valuable indicator of prognosis of MDS patients.