Metabolomics in the study of kidney diseases. Nat Rev Nephrol. 2012;8:22-33. [PMID: 22025087 DOI: 10.1038/nrneph]

High glucose/ChREBP-induced Hif-1α transcriptional activation in CD4+ T cells reduces the risk of diabetic kidney disease by inhibiting the Th1 response

AIMS/HYPOTHESIS

Diabetic kidney disease (DKD) features intrarenal inflammation, in which T cells play a part. Hypoxia-inducible factor-1α (HIF-1α), a key transcription factor regulating cellular responses to hypoxia, is reportedly involved in the course of inflammation. The role of HIF-1α in DKD has been investigated, but the conclusions are controversial so far. We report a previously unrecognised high glucose/carbohydrate response element binding protein (ChREBP)/Hif-1α transcription axis in CD4+ T cells.

METHODS

Lck-Cre+Hif1aloxp/loxp (Hif-1α-/-) mice were generated to explore the role of T cell HIF-1α in the pathogenesis of DKD. CD4+ T cells sorted from T cell-specific Hif-1α-ablated mice and wild-type mice were used for functional studies and transcriptional profiling.

RESULTS

In this study, we used Lck-Cre transgenic mice to specifically disrupt Hif-1α in T cells and found that ablation of Hif-1α greatly accelerated the progression of DKD in a streptozocin-induced model of diabetes. Adoptive transfer of splenic CD4+ T cells from Hif-1α-/- mice rather than wild-type controls to diabetic mice elicited severe renal damage. Compared with wild-type controls, Hif-1α knockout markedly promoted IFN-γ secretion by CD4+ T cells in response to high glucose. Additional Ifn-γ ablation negated the effect of Hif-1α knockout on DKD progression. Mechanistically, the background Hif-1α mRNA synthesis rate in resting T cells was very low, but culture of T cells under high glucose led to significantly promoted Hif-1α expression, which was dependent on the transcription factor ChREBP. Consistent with results from Hif-1α-/- CD4+ T cells, adoptive transfer of Chrebp-/- CD4+ T cells to wild-type diabetic mice also elicited severe diabetic renal damage. By contrast, Chrebp-/-Ifn-γ-/- CD4+ T cells failed to show nephrotoxic effects. Examination of the Hif-1α promoter identified a ChREBP-binding sequence that mediated transcriptional upregulation of Hif-1α by high glucose.

CONCLUSIONS/INTERPRETATION

Our study reveals a previously unrecognised high glucose/ChREBP/Hif-1α transcription axis in CD4+ T cells, which serves as a self-protection mechanism against DKD progression via limiting T helper 1 response.

Establishment and evaluation of a risk prediction model for coronary heart disease in primary Sjögren's syndrome based on peripheral blood IL-6 and Treg percentages

Objective

This study aims to establish and evaluate a risk prediction model for coronary heart disease (CHD) in patients with primary Sjögren's syndrome (pSS) based on peripheral blood levels of interleukin-6 (IL-6) and the percentage of regulatory T cells (Treg%). This model is intended to facilitate the timely identification of high-risk patients and the implementation of preventive measures.

Methods

Clinical data were collected from 120 pSS patients who visited the Second Hospital of Shanxi Medical University between November 2021 and September 2023. Patients were classified into pSS and pSS-CHD groups according to CHD diagnostic criteria. Peripheral blood lymphocyte subsets and cytokine levels were assessed using flow cytometry. Univariate and multivariate logistic regression analyses were employed to identify independent risk factors, and a nomogram was constructed based on these factors. The model's discriminatory ability, calibration, and clinical utility were evaluated using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis.

Results

The univariate and multivariate logistic regression analyses identified several independent risk factors for CHD in pSS patients: erythrocyte sedimentation rate (ESR) (OR=1.10, P=0.019), triglycerides (TG) (OR=3.67, P=0.041), IL-6 (OR=1.29, P=0.048), and Treg% (OR=0.25, P=0.004). A nomogram incorporating these factors demonstrated an area under the curve (AUC) of 0.96, indicating excellent predictive performance, and showed good calibration (P=0.599), suggesting significant clinical applicability. Furthermore, Treg% exhibited a negative correlation with cholesterol (CHOL) and low-density lipoprotein cholesterol (LDL-C) levels, while IL-6 showed a positive correlation with CHOL and LDL-C levels. TG was positively correlated with C-reactive protein (CRP).

Conclusion

This study successfully developed a risk prediction model based on peripheral blood IL-6 and Treg% levels, providing critical evidence for the early identification and personalized prevention of CHD in pSS patients, with potential clinical implications.

Optimal Perioperative Antimicrobial Management Strategies of Kidney Transplant Recipients Guided by Metagenomic Next-Generation Sequencing of Deceased Donors' Microbiology Samples

Background

There is no consensus on the optimal use of perioperative antibiotics prophylaxis after kidney transplantation, but there is a common trend to limit the duration of antibiotic use worldwide. Metagenomic next-generation sequencing (mNGS) has emerged as a novel technology for pathogen detection in clinical practice due to its noninvasive, rapid, precise and high susceptibility to detect infectious pathogens. However, data are lacking on whether mNGS analyses could be used to detect pathogens and guide anti-infection regimens in kidney transplant donors and recipients.

Methods

We conducted a retrospective study to review all clinic data of mNGS and traditional laboratory methods (TMs) for pathogen detection in kidney transplant recipients and their corresponding deceased donors from August 1, 2021 to October 30, 2022 in our center.

Results

A total of 57 donors and 112 of their corresponding recipients were included. The antimicrobial strategy mainly depended on mNGS results combined with traditional pathogen culture and clinical conditions. The percentages of positive pathogen detected by mNGS in blood, urine, bronchoalveolar lavage fluid (BALF) and preservation fluids (PFs) were 50.9% (29/57), 35.1% (20/57), 84.2% (48/57) and 54.4% (31/57) respectively, and were 24.6% (14/57), 15.8% (9/57), 57.9% (33/57) and 14.1% (8/57) respectively when using TMs. mNGS could detected all of pathogens which were detected by TMs. However, samples with negative TMs testing can be additionally detected as positive by mNGS (15/43 in blood, 11/48 in urine, 15/24 in BALF and 23/49 in PFs). Drug resistance genes were detected in 9 donors by mNGS,which were consistent with 6 donors by TMs. There was only one case of donor-derived infection in this study.

Conclusion

This study showed that it is effective to combine mNGS with traditional pathogen detection methods and clinical features to develop optimal perioperative antimicrobial management strategies for deceased donor kidney transplantation.

Global-feature of autoimmune glomerulonephritis using proteomic analysis of laser capture microdissected glomeruli

Background

IgA nephropathy (IgAN), (LN), membranous nephropathy (MN), and minimal change nephropathy (MCN) are all belonged to autoimmune glomerulonephritis. This study aimed to identify the specific proteomic characteristics of the four GNs diseases in order to provide frameworks for developing the appropriate drug for patients diagnosed with GNs disease.

Methods

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was utilized to investigate proteomic features of glomerular tissues obtained by laser capture microdissection (LCM). 8 normal control cases, 11 IgAN cases, 19 LN cases, 5 MN cases, and 3 MCN cases in this study were selected for bioinformatics analyses.

Results

The shared overlapping proteins among the top 100 DEPs of each GNs type were mostly downregulated, in which only FLII was significantly downregulated in the four GNs diseases. A2M was significantly upregulated in MN, IgAN, and LN subgroups. The pathway of complement and coagulation cascades was notably activated with NES value ranging 2.77 to 3.39 among MCN, MN, IgAN, and LN diseases, but the pattern of protein expression level were significantly different. In LN patients, the increased activity of complement and coagulation cascades was contributed by the high expression of multiple complements (C1QB, C3, C4A, C4B, C6, C8B, C8G, C9). Meanwhile, both C1QC and C4B were remarkably upregulated in MN patients. On the contrary, complement-regulating proteins (CD59) was substantially decreased in MCN and IgAN subgroup.

Conclusions

The integrative proteomics analysis of the four GNs diseases provide insights into unique characteristics of GNs diseases and further serve as frameworks for precision medicine diagnosis and provide novel targets for drug development.

Rituximab in relapsing and de novo MPO ANCA-associated vasculitis with severe renal involvement: a case series

BACKGROUND

Antineutrophil cytoplasmic antibody associated vasculitis (AAV) is a group of diseases associated in most cases with the presence of anti-neutrophil cytoplasmic antibodies (ANCAs). Rituximab- based remission induction has been proven effective in ANCA associated vasculitis but scarce data exist in forms with severe renal involvement. In this case series, we report the outcomes in patients with de novo or recurrent MPO-AAV and severe renal involvement treated with rituximab without cyclophosphamide (CYC).

METHODS

In this single centre retrospective study, we analysed patients with a clinical diagnosis of de novo or recurrent AAV who met the following criteria: detection of P-ANCA, creatinine clearance lower than 30 ml/min, induction of remission therapy with rituximab without concomitant CYC and a follow up period of at least 6 months. The primary outcomes were complete remission after induction therapy, renal function recovery and mortality after the induction treatment.

RESULTS

Eight patients met the inclusion criteria. The M:F ratio was 1:7, the average age was 54 years old and the median follow up was 10 months (7-72); in 2 patients there was a MPA renal limited vasculitis. A renal biopsy was performed in 7 patients. The median BVAS score at rituximab induction was 14(range 6-21). Two patients required haemodialysis before the induction treatment. Four patients developed end stage renal disease (ESRD) that required haemodialysis. These data show a remission of the disease, associated with a stabilization of the kidney function in 50% of patients. In 3 patients who did not show a response, there was also no response to CYC.

CONCLUSIONS

This study shows a partial efficacy of rituximab in renal function recovery and a low risk of infectious complications in patients with MPO vasculitis with severe renal involvement, in particular in the short term. The optimal treatment in this subgroup of patients still has to be established because data are lacking.

The role of podocytes dysfunction in chronic glomerulonephritis progression

In the review, the mechanisms of podocytes damage underlying the development of proteinuria and progression of glomerulosclerosis in chronic glomerulonephritis are discussed in detail. The results of experimental and clinical studies are presented. Under the different immune and non-immune factors the podocytes form a stereotyped response to damage consisting in the reorganization of the actin cytoskeleton, foot process effacement, the detachment of podocytes from the glomerular basement membrane, and the appearance of specific podocyte proteins and whole cells (podocyturia) in the urine. Massive podocyturia in a limited proliferative capacity of podocytes leads to reduce their total count in the glomerulus (podocytopenia) and the development of glomerulosclerosis. The authors describe the line of markers of the podocyte injury and invasive and non-invasive methods of their assessment. In addition, the relationship of podocyturia level with proteinuria and renal dysfunction are discussed, the prospects of assessment the podocyte proteins in urine for assessing of glomerular damage severity and glomerulosclerosis risk are examined.

Metabolic analysis and mechanism of lipids, amino acids and carbohydrates in gastrointestinal cancer

Metabolomics has recently been applied in a variety of biomedical research fields. However, there have been no articles on the application of metabonomics in gastrointestinal cancer and the relevant detailed mechanisms. In this article, the application of metabolomics in early diagnosis of gastrointestinal cancer is reviewed, and the metabolic role and metabolic mechanism of lipids, amino acids and carbohydrates, as well as the future challenge of metabolomics in the clinical application are summarized.