Interleukin-9 mediates chronic kidney disease-dependent vein graft disease: a role for mast cells

Exploring the gut mycobiome: differential composition and clinical associations in hypertension, chronic kidney disease, and their comorbidity

Background

Hypertension (HTN) and chronic kidney disease (CKD) pose significant global health challenges and often coexist, amplifying cardiovascular risks. Recent attention has turned to the gut mycobiome as a potential factor in their pathophysiology. Our study sought to examine the gut fungal profile in individuals with HTN, CKD, and the concurrent HTN+CKD condition, investigating its connections with serum cytokines, renal function, and blood pressure.

Methods and materials

We investigated three distinct participant groups: a cohort of 50 healthy controls (HC), 50 individuals diagnosed with HTN-only, and 50 participants suffering from both HTN and CKD (HTN+CKD). To facilitate our research, we gathered fecal and blood samples and conducted a comprehensive analysis of serum cytokines. Moreover, fungal DNA extraction was conducted with meticulous care, followed by sequencing of the Internal Transcribed Spacer (ITS) region.

Results

HTN+CKD patients displayed distinctive fungal composition with increased richness and diversity compared to controls. In contrast, HTN-only patients exhibited minimal fungal differences. Specific fungal genera were notably altered in HTN+CKD patients, characterized by increased Apiotrichum and Saccharomyces levels and reduced Candida abundance. Our correlation analyses revealed significant associations between fungal genera and serum cytokines. Moreover, certain fungal taxa, such as Apiotrichum and Saccharomyces, exhibited positive correlations with renal function, while others, including Septoria, Nakaseomyces, and Saccharomyces, were linked to blood pressure, particularly diastolic pressure.

Conclusion

Gut mycobiome dysbiosis in individuals with comorbid HTN and CKD differs significantly from that observed in HTN-only and healthy controls. The interactions between serum cytokines, renal function, and blood pressure emphasize the potential impact of the fungal microbiome on these conditions. Additional research is required to clarify the underlying mechanisms and identify therapeutic opportunities associated with mycobiome dysbiosis in HTN and CKD.

Mast cell activation and degranulation in acute artery injury: A target for post-operative therapy

The increasing incidence of cardiovascular disease (CVD) has led to a significant ongoing need to address this surgically through coronary artery bypass grafting (CABG) and percutaneous coronary interventions (PCI). From this, there continues to be a substantial burden of mortality and morbidity due to complications arising from endothelial damage, resulting in restenosis. Whilst mast cells (MC) have been shown to have a causative role in atherosclerosis and other vascular diseases, including restenosis due to vein engraftment; here, we demonstrate their rapid response to arterial wire injury, recapitulating the endothelial damage seen in PCI procedures. Using wild-type mice, we demonstrate accumulation of MC in the femoral artery post-acute wire injury, with rapid activation and degranulation, resulting in neointimal hyperplasia, which was not observed in MC-deficient KitW-sh/W-sh mice. Furthermore, neutrophils, macrophages, and T cells were abundant in the wild-type mice area of injury but reduced in the KitW-sh/W-sh mice. Following bone-marrow-derived MC (BMMC) transplantation into KitW-sh/W-sh mice, not only was the neointimal hyperplasia induced, but the neutrophil, macrophage, and T-cell populations were also present in these transplanted mice. To demonstrate the utility of MC as a target for therapy, we administered the MC stabilizing drug, disodium cromoglycate (DSCG) immediately following arterial injury and were able to show a reduction in neointimal hyperplasia in wild-type mice. These studies suggest a critical role for MC in inducing the conditions and coordinating the detrimental inflammatory response seen post-endothelial injury in arteries undergoing revascularization procedures, and by targeting the rapid MC degranulation immediately post-surgery with DSCG, this restenosis may become a preventable clinical complication.

Incidence of arterial steno-occlusive disease and related factors in patients undergoing coronary artery bypass graft surgery

Background: Patients who undergo coronary artery bypass graft (CABG) surgery receive regular physical examinations and medications on an outpatient basis. However, these patients are at risk of developing other vascular diseases, such as postoperative arterial steno-occlusive disease (SOD). This study investigated the incidence of SOD and related factors.Methods: In total, 246 patients who underwent CABG surgery from January 1, 2017 to December 31, 2021 were investigated. The incidence and risk factors of vascular disease were analyzed by dividing the included patients into SOD and non-SOD groups. Laboratory tests, medical history, surgical information, and family history were investigated through an electronic chart review.Results: Data from 193 patients who met the criteria were analyzed. SOD occurred in 19.1% of patients, and the cerebral artery (38%) was the most common artery involved, followed by the peripheral artery (32%), the coronary artery (22%), and the retinal artery (8%). Risk factors for the development of SOD included estimated glomerular filtration rate (eGFR; odds ratio [OR]=0.977, p=0.008), cholesterol (OR=1.020, p=0.001), and patients with diabetes complications (OR=5.077, p=0.010). The 3-year cumulative incidence rate was 21.6%, and the risk factors for cumulative occurrence were a low eGFR, elevated cholesterol, and complications of diabetes.Conclusions: Low eGFR, high cholesterol, and the presence of diabetic complications before CABG surgery may be associated with postoperative vascular disease. In these cases, close monitoring, proper drug administration, and patient warnings may be required.

Construction and Analysis of Immune Infiltration-Related ceRNA Network for Kidney Stones

Purpose: Kidney stones is a common medical issue that mediates kidney injury and even kidney function loss. However, the exact pathogenesis still remains unclear. This study aimed to explore the potential competing endogenous RNA (ceRNA)-related pathogenesis of kidney stones and identify the corresponding immune infiltration signature. Methods: One mRNA and one long non-coding RNA (lncRNA) microarray dataset was obtained from the GEO database. Subsequently, we compared differentially expressed mRNAs (DE-mRNAs) and lncRNAs between Randall's plaques in patients with calcium oxalate (CaOx) stones and controls with normal papillary tissues. lncRNA-targeted miRNAs and miRNA-mRNA pairs were predicted using the online databases. lncRNA-related DE-mRNAs were identified using the Venn method, and GO and KEGG enrichment analyses were subsequently performed. The immune-related lncRNA-miRNA-mRNA ceRNA network was developed. The CIBERSORT algorithm was used to estimate the rate of immune cell infiltration in Randall's plaques. The ceRNA network and immune infiltration were validated in the glyoxylate-induced hyperoxaluric mouse model and oxalate-treated HK-2 cells. Results: We identified 2,340 DE-mRNAs and 929 DE-lncRNAs between Randall's plaques in patients with CaOx stones and controls with normal papillary tissues. lncRNA-related DE-mRNAs were significantly enriched in extracellular matrix organization and collagen-containing extracellular matrix, which were associated with kidney interstitial fibrosis. The immune-related ceRNA network included 10 lncRNAs, 23 miRNAs, and 20 mRNAs. Moreover, we found that M2 macrophages and resting mast cells were differentially expressed between Randall's plaques and normal tissues. Throughout kidney stone development, kidney tubular injury, crystal deposition, collagen fiber deposition, TGF-β expression, infiltration of M1 macrophages, and activation of mast cells were more frequent in glyoxylate-induced hyperoxaluric mice compared with control mice. Nevertheless, M2 macrophage infiltration increased in early stages (day 6) and decreased as kidney stones progressed (day 12). Furthermore, treatment with 0.25 and 0.5 mM of oxalate for 48 h significantly upregulated NEAT1, PVT1, CCL7, and ROBO2 expression levels and downregulated hsa-miR-23b-3p, hsa-miR-429, and hsa-miR-139-5p expression levels in the HK-2 cell line in a dose-dependent manner. Conclusion: We found that significant expressions of ceRNAs (NEAT1, PVT1, hsa-miR-23b-3p, hsa-miR-429, hsa-miR-139-5p, CCL7, and ROBO2) and infiltrating immune cells (macrophages and mast cells) may be involved in kidney stone pathogenesis. These findings provide novel potential therapeutic targets for kidney stones.

The Pathogenesis of End-Stage Renal Disease from the Standpoint of the Theory of General Pathological Processes of Inflammation

Chronic kidney disease can progress to end-stage chronic renal disease (ESRD), which requires the use of replacement therapy (dialysis or kidney transplant) in life-threatening conditions. In ESRD, irreversible changes in the kidneys are associated with systemic changes of proinflammatory nature and dysfunctions of internal organs, skeletal muscles, and integumentary tissues. The common components of ESRD pathogenesis, regardless of the initial nosology, are (1) local (in the kidneys) and systemic chronic low-grade inflammation (ChLGI) as a risk factor for diabetic kidney disease and its progression to ESRD, (2) inflammation of the classical type characteristic of primary and secondary autoimmune glomerulonephritis and infectious recurrent pyelonephritis, as well as immune reactions in kidney allograft rejection, and (3) chronic systemic inflammation (ChSI), pathogenetically characterized by latent microcirculatory disorders and manifestations of paracoagulation. The development of ChSI is closely associated with programmed hemodialysis in ESRD, as well as with the systemic autoimmune process. Consideration of ESRD pathogenesis from the standpoint of the theory of general pathological processes opens up the scope not only for particular but also for universal approaches to conducting pathogenetic therapies and diagnosing and predicting systemic complications in severe nephropathies.

A Novel Risk Scoring Tool to Predict Saphenous Vein Graft Occlusion After Cardiac Artery Bypass Graft Surgery

Objectives: Coronary artery bypass grafting (CABG) success is reduced by graft occlusion. Understanding factors associated with graft occlusion may improve patient outcomes. The aim of this study was to develop a predictive risk score for saphenous vein graft (SVG) occlusion after CABG.

Methods: This retrospective cohort study enrolled 3,716 CABG patients from January 2012 to March 2013. The development cohort included 2,477 patients and the validation cohort included 1,239 patients. The baseline clinical data at index CABG was analyzed for their independent impact on graft occlusion in our study using Cox proportional hazards regression. The predictive risk scoring tool was weighted by beta coefficients from the final model. Concordance (c)-statistics and comparison of the predicted and observed probabilities of predicted risk were used for discrimination and calibration.

Results: A total of 959 (25.8%) out of 3,716 patients developed at least one late SVG occlusion. Significant risk factors for occlusion were female sex [beta coefficients (β) = 0.52], diabetes (β = 0.21), smoking (currently) (β = 0.32), hyperuricemia (β = 0.22), dyslipidemia (β = 0.52), prior percutaneous coronary intervention (PCI) (β = 0.21), a rising number of SVG (β = 0.12) and lesion vessels (β = 0.45). On-pump surgery (β = −0.46) and the use of angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) (β = −0.59) and calcium channel blockers (CCB) (β = −0.23) were protective factors. The risk scoring tool with 11 variables was developed from the derivation cohort, which delineated each patient into risk quartiles. The c-statistic for this model was 0.71 in the validation cohort.

Conclusions: An easy-to-use risk scoring tool which included female sex, diabetes, smoking, hyperuricemia, dyslipidemia, prior PCI, a rising number of SVG and lesion vessels, on-pump surgery, the use of ACEI/ ARB and CCB was developed and validated. The scoring tool accurately estimated the risk of late SVG occlusion after CABG (c-statistic = 0.71).

Expression and clinical significance of interleukin-9 in renal tumors

Background

To measure expression levels of interleukin-9 (IL-9) in renal tumors and to determine the clinical significance of those levels.

Methods

Using TCGA database analysis, we found that the expression of IL-9 in renal clear cell carcinoma was significantly down-regulated, and was significantly related to survival. We then verified this using experiments. We enrolled 66 patients who underwent surgical resection of renal tumors between January and December 2018 at the First Affiliated Hospital of Soochow University. Their tumor tissues were paired with adjacent normal tissues and IL-9 expression levels were measured using immunohistochemistry. We determined the correlation of IL-9 expression with clinicopathological features and progression-free survival (PFS).

Results

Expression of IL-9 in renal tumors was significantly lower than in adjacent normal tissues (P<0.0001). There was a significant negative correlation between IL-9 expression levels and R.E.N.A.L. scores (P=0.0277) as well as with differentiation (P=0.0041). However, no significant correlation was found between IL-9 levels and clinicopathological features, including gender (P=0.0716), age (P=0.2566), body mass index (BMI) (P=0.7941), tumor size (P=0.4193) or TNM staging (P=0.5402). PFS time in renal tumor patients with positive IL-9 expression was similar to that of patients with negative IL-9 expression.

Conclusions

IL-9 expression was higher in adjacent normal tissues than in renal tumors. Low expression of IL-9 was detected when R.E.N.A.L. score was high or cell differentiation was poor, suggesting that IL-9 may may play a protective role in renal tumor microenvironments.

Development of a risk score for early saphenous vein graft failure: An individual patient data meta-analysis

OBJECTIVES

Early saphenous vein graft (SVG) occlusion is typically attributed to technical factors. We aimed at exploring clinical, anatomical, and operative factors associated with the risk of early SVG occlusion (within 12 months postsurgery).

METHODS

Published literature in MEDLINE was searched for studies reporting the incidence of early SVG occlusion. Individual patient data (IPD) on early SVG occlusion were used from the SAFINOUS-CABG Consortium. A derivation (n = 1492 patients) and validation (n = 372 patients) cohort were used for model training (with 10-fold cross-validation) and external validation respectively.

RESULTS

In aggregate data meta-analysis (48 studies, 41,530 SVGs) the pooled estimate for early SVG occlusion was 11%. The developed IPD model for early SVG occlusion, which included clinical, anatomical, and operative characteristics (age, sex, dyslipidemia, diabetes mellitus, smoking, serum creatinine, endoscopic vein harvesting, use of complex grafts, grafted target vessel, and number of SVGs), had good performance in the derivation (c-index = 0.744; 95% confidence interval [CI], 0.701-0.774) and validation cohort (c-index = 0.734; 95% CI, 0.659-0.809). Based on this model. we constructed a simplified 12-variable risk score system (SAFINOUS score) with good performance for early SVG occlusion (c-index = 0.700, 95% CI, 0.684-0.716).

CONCLUSIONS

From a large international IPD collaboration, we developed a novel risk score to assess the individualized risk for early SVG occlusion. The SAFINOUS risk score could be used to identify patients that are more likely to benefit from aggressive treatment strategies.

Interleukin-9 protects from early podocyte injury and progressive glomerulosclerosis in Adriamycin-induced nephropathy

A wide spectrum of immunological functions has been attributed to Interleukin 9 (IL-9), including effects on the survival and proliferation of immune and parenchymal cells. In recent years, emerging evidence suggests that IL-9 expression can promote tissue repair in inflammatory conditions. However, data about the involvement of IL-9 in kidney tissue protection is very limited. Here, we investigated the role of IL-9 in Adriamycin-induced nephropathy (AN), a mouse model for proteinuric chronic kidney disease. Compared to wild type mice, IL-9 knockout (Il9^-/-) mice with AN displayed accelerated development of proteinuria, aggravated glomerulosclerosis and deterioration of kidney function. At an early stage of disease, the Il9^-/- mice already displayed a higher extent of glomerular podocyte injury and loss of podocyte number compared to wild type mice. In the kidney, T cells and innate lymphoid cells produced IL-9. However, selective deficiency of IL-9 in the innate immune system in Il9^-/-Rag2^-/- mice that lack T and B cells did not alter the outcome of AN, indicating that IL-9 derived from the adaptive immune system was the major driver of tissue protection in this model. Mechanistically, we could show that podocytes expressed the IL-9 receptor in vivo and that IL-9 signaling protects podocytes from Adriamycin-induced apoptosis in vitro. Finally, in vivo treatment with IL-9 effectively protected wild type mice from glomerulosclerosis and kidney failure in the AN model. The detection of increased serum IL-9 levels in patients with primary focal and segmental glomerulosclerosis further suggests that IL-9 production is induced by glomerular injury in humans. Thus, IL-9 confers protection against experimental glomerulosclerosis, identifying the IL-9 pathway as a potential therapeutic target in proteinuric chronic kidney disease.

Inhibition of Histone H3K27 Acetylation Orchestrates Interleukin-9-Mediated and Plays an Anti-Inflammatory Role in Cisplatin-Induced Acute Kidney Injury

Nephrotoxicity is a major side effect of cisplatin (CP)- and platinum-related chemotherapy, and inflammation contributes to disease pathogenesis. Interleukin-9 (IL-9) is a pleiotropic cytokine associated with inflammation. Here, we investigated the key role of IL-9 as a regulator of protective mechanisms in CP-induced acute kidney injury (AKI). We observed that IL-9 was decreased not only in a CP-induced AKI mouse model but also in THP-1 and RAW264.7 cell lines. Seventy-two hours post-CP injection, renal dysfunction and tubule injury were significantly attenuated in IL-9 overexpression adeno-associated virus 9 (AAV9)-treated mice. The levels of serum urea, serum creatinine, kidney injury molecule-1 (KIM-1), and histological damage were partially diminished following treatment with IL-9. The renoprotective effects of IL-9 may be attributed to the regulation of cytokines, and we found that IL-9 acted on macrophages in a regulatory manner, promoting an anti-inflammatory phenotype. Furthermore, IL-9 enhanced the suppression of macrophage-driven renal inflammation. Inhibition of H3K27 acetylation orchestrated IL-9-mediated renoprotection in CP-induced AKI. Thus, our findings indicate novel and potent anti-inflammatory properties of IL-9 that confer preservation of kidney function and structure in CP-induced AKI, which may counteract kidney disease procession.