Kidney & blood pressure research最新文献

Introduction: Accumulating evidence has disclosed that IgA nephropathy (IgAN) could present shortly after the second dose of COVID-19 mRNA vaccine. However, the undying mechanism remains unclear and we aimed to investigate the potential molecular mechanisms.

Methods: We downloaded gene expression datasets of COVID-19 mRNA vaccination (GSE201535) and IgAN (GSE104948). Weighted Gene Co-Expression Network Analysis (WGCNA) was performed to identify co-expression modules related to the second dose of COVID-19 mRNA vaccination and IgAN. Differentially expressed genes (DEGs) were screened, and a transcription factor (TF)-miRNA regulatory network and protein-drug interaction were constructed for the shared genes.

Results: WGCNA identified one module associated with the second dose of COVID-19 mRNA vaccine and four modules associated with IgAN. Gene ontology (GO) analyses revealed enrichment of cell cycle-related processes for the COVID-19 mRNA vaccine hub genes and immune effector processes for the IgAN hub genes. We identified 74 DEGs for the second dose of COVID-19 mRNA vaccine and 574 DEGs for IgAN. Intersection analysis with COVID-19 vaccine-related genes led to the identification of two shared genes, TOP2A and CEP55. The TF-miRNA network analysis showed that hsa-miR-144 and ATF1 might regulate the shared hub genes.

Conclusions: This study provides insights into the common pathogenesis of COVID-19 mRNA vaccination and IgAN. The identified pivotal genes may offer new directions for further mechanistic studies of IgAN secondary to COVID-19 mRNA vaccination.

Introduction: The correlation between hypercholesterolemia and cardiovascular disease in kidney transplant recipients (KTRs) remains uncertain. We sought to characterize the association between abnormal cholesterol profiles and cardiovascular morbidity and mortality in this unique population.

Methods: This retrospective cohort study was conducted at a single center and included all adult KTR, transplanted between January 2005 and April 2014. The primary outcome was major adverse cardiovascular events (MACE) while the secondary outcome was the composite outcome of MACE and all-cause mortality. Exposure to abnormal cholesterol levels was calculated using a time-weighted average calculation. MACE and mortality risk were analyzed using a multivariate time-varying Cox model.

Results: The final cohort comprised 737 KTR, with a median follow-up of 2,920 days. A total of 126 patients (17.1%) experienced MACE. High LDL-C levels and MACE risk were correlated by multivariate analysis (HR 1.008 per mg/dL, 95% CI: 1.001-1.016), while low HDL-C levels were not significantly associated with MACE (HR 0.992 per mg/dL, 95% CI: 0.976-1.009). A higher LDL-C/HDL-C ratio was significantly associated with an increased risk of MACE in multivariate analyses (HR 1.502 per unit, 95% CI: 1.147-1.968), and also correlated with the composite outcome (HR 1.35 per unit, 95% CI: 1.06-1.71).

Conclusions: A high LDL-C/HDL-C ratio is predictive of an increased risk of cardiovascular morbidity and mortality in KTRs. These findings emphasize the significance of the LDL-C/HDL-C ratio as a valuable marker of cardiovascular risk and support current recommendations to improve hypercholesterolemia in this high-risk group.

Introduction: The aim of the presented prospective observational study was to evaluate the effect of fistula flow on peripheral wave morphology and pulse wave velocity by means of the oscillometric Vicorder®-device with the purpose of fistula surveillance.

Methods: Digitized and normalized curves of 53 haemodialysis patients at the fistula and non-fistula arm were analysed. Slope parameters and the areas under the curve of characteristic sections of pulse waves as well as the power spectrum of the pulse waves and their first and second derivatives were computed. Furthermore, the amplitude of volumetric change (AMP) was assessed. Duplex sonography served as a reference method.

Results: In the comprehensive set of novel pulse wave parameters significant inter-arm differences were demonstrated and a significant delay of the systolic maximum at the fistula arm in comparison to the non-fistula arm (204 ± 3.4 vs. 162 ± 5.3 ms, p < 0.001) was proven. Unexpectedly, pulse wave velocity apparently did not differ between both arms (7.85 vs. 8.05 m/s at the fistula/non-fistula side, p = 0.942). The inter-arm differences of the slope parameters were more pronounced in forearm than in upper arm fistulas. Finally, we showed that the inter-arm difference of AMP correlated with volume flow (r = 0.326 with p = 0.017).

Conclusion: Pulse waves as assessed by oscillometric pulse wave analysis have distinct features at fistula and non-fistula arms. This is due to enhanced arteriovenous flow, i.e. in both the brachial artery and the fistula vein. The analysis of those alterations has the potential to assess fistula function.

Introduction: The calcineurin inhibitor cyclosporine A (CsA) has been shown to effectively reduce proteinuria. However, its precise mechanism is still not fully understood. Our previous study showed that CsA reduced proteinuria by directly stabilizing the foot process (FP) cytoskeletal structure via cofilin-1, suggesting that synaptopodin, a podocyte-specific actin protein, is not the sole target of CsA in podocytes.

Methods: In this study, we established an adriamycin (ADR)-induced nephropathy rat model and a cultured podocyte injury model. We employed Western blotting and immunofluorescence techniques to assess the expression and distribution of transgelin, Krüppel-like factor-4 (KLF-4), nephrin, and synaptopodin.

Results: We observed a significant increase in proteinuria levels accompanied by loss of normal FP structure in the ADR-induced nephropathy rat model. The levels of the actin cross-linking protein transgelin were increased significantly, while those of the podocyte-specific molecules nephrin and synaptopodin were decreased in vivo. Treatment with CsA effectively reduced proteinuria while restoring FP effacement stability in ADR-induced nephropathy models and restoring the expression of transgelin, nephrin, and synaptopodin both in vivo and in vitro. Furthermore, CsA treatment dose-dependently decreased transgelin levels while significantly increasing KLF-4 expression in injured podocytes. In addition, CsA failed to downregulate transgelin when KLF-4 was specifically knocked down.

Conclusion: Our findings suggest that CsA protects against podocyte injury by downregulating abnormally high levels of transgelin via upregulation of KLF-4 expression.

Introduction: Contrast nephropathy (CN) is characterized by oxidative stress, vasoconstriction, tubular toxicity, and hypoxia of the renal medulla. We aimed to test the therapeutic effects of an α7 nicotinic acetylcholine receptor (nAChR) agonist, GTS-21, in an experimental CN model.

Methods: Male Sprague-Dawley rats (n = 40) were divided into 4 groups: saline-treated control, GTS-21-treated control, contrast, and GTS-21-treated contrast groups. Starting on the 1st day, GTS-21 (4 mg/kg, intraperitoneally) or saline was administered twice a day for 3 days. CN was induced on the second day by intravenous injection of indomethacin (10 mg/kg), l-NAME (10 mg/kg), and a contrast agent with high osmolarity (6 mL/kg; Urografin 76%). At the 72nd hour, blood and kidney samples were obtained for the determination of biochemical, histological, and gene expression parameters.

Results: Compared to those in control rats, the elevated serum BUN level in the contrast group decreased with GTS-21 treatment, while H&E staining and TUNEL assays showed that contrast-induced renal injury was improved by GTS-21. Moreover, GTS-21 treatment in the CN also increased the antioxidant glutathione level. In the contrast group, a significant increase in IL-6 expression and a decrease in TGF-β expression were observed; however, GTS-21 treatment decreased IL-6 expression and increased TGF-β expression.

Conclusion: GTS-21 significantly alleviated renal injury parameters through antioxidant, anti-inflammatory, and antiapoptotic mechanisms in the CN model.

Introduction: Patients undergoing hemodialysis (HD) are highly vulnerable during the COVID-19 pandemic. We aimed to investigate the risk factors associated with the severity of COVID-19 and death after the complete liberalization of epidemic control in China.

Methods: We followed the outcomes of the HD patients of Central Hospital of Dalian University of Technology, from December 6, 2022, to January 8, 2023. The non-contrast-enhanced chest computed tomography (CT) was performed on all COVID-19-infected hospitalized patients. We recorded the patient's clinical characteristics, demographic features, vaccination history, treatments, and lung lesions. Odds ratios and 95% confidence intervals were calculated using logistic regression models to identify independent risk factors for COVID-19-related severity and mortality.

Results: This study included a total of 858 HD patients, of which 660 were infected with COVID-19. The mean age was (55.61 ± 14.61) years, with a median (interquartile range) dialysis duration of 44.5 (69.5) months. Over half (60%) of the study participants were male, and the majority had hypertension as a comorbidity. Multivariable analysis revealed that age, pre-dialysis diastolic pressure, fever, white blood cell (WBC) count, potassium, β2-microglobulin level, and calcium were independent risk factors for disease severity, while platelets, urea nitrogen, serum chlorine and creatinine were identified as independent protective factors. Furthermore, total iron-binding capacity and vaccination were found to be independent protective factors against mortality, and WBC count was an independent risk factor for in-hospital mortality (p < 0.05). The most frequent CT finding among hospitalized patients with chest symptoms was patchy shadow or pleural effusion, observed in 64.8% of cases. More than half of the patients exhibited bilateral lung lesions, and over 60% involved two or more lobes.

Conclusion: The majority of HD patients are susceptible to COVID-19. Demographic, clinical features, and laboratory indicators can be used to predict the severity and mortality associated with COVID-19. Our findings will assist clinicians in identifying markers for the early detection of high mortality risk in HD patients with COVID-19.

Introduction: Renal cell carcinoma (RCC) is a common type of kidney cancer with limited treatment options and a high mortality rate. Therefore, it is essential to understand the role and mechanism of key genes in RCC development and progression. This study aimed to analyze the role of zinc fingers and homeoboxes 2 (ZHX2) in RCC and the underlying mechanism.

Methods: RNA expression was analyzed by quantitative real-time polymerase chain reaction, while protein expression was analyzed by Western blotting assay and immunohistochemistry assay. Cell viability was evaluated using CCK-8 assay, and cell proliferation was assessed by EdU assay. The rate of cell apoptosis was quantified by flow cytometry. Transwell assays were conducted to analyze cell migration and invasion. The sphere formation assay was performed to assess the formation of microspheres. Additionally, m6A RNA immunoprecipitation assay and RNA immunoprecipitation assay were utilized to investigate the relationship between ZHX2 and two proteins, methyltransferase like 3 (METTL3) and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1). The stability of ZHX2 mRNA was analyzed through the Actinomycin D assay. Furthermore, a xenograft mouse model assay was conducted to analyze the effect of ZHX2 overexpression and METTL3 silencing on RCC cell tumor properties in vivo.

Results: ZHX2 expression was upregulated in both RCC tissues and cells when compared with healthy renal tissues and human renal cortex proximal convoluted tubule epithelial cells. Depletion of ZHX2 inhibited RCC cell proliferation, migration, invasion, and spheroid-forming capacity but promoted cell apoptosis. Moreover, it was found that METTL3-mediated m6A methylation of ZHX2 and IGF2BP1 also stabilized ZHX2 through m6A methylation modification. Furthermore, ZHX2 overexpression showed a potential for attenuating the effects induced by METTL3 silencing and counteracted the inhibitory effect of METTL3 depletion on tumor formation in vivo.

Conclusion: METTL3 and IGF2BP1-mediated m6A modification of ZHX2 promoted RCC progression. The finding suggests that ZHX2 may serve as a potential therapeutic target in RCC, providing valuable insights for future clinical interventions.

Background: Physical performance is poorly addressed in dialysis patients, due to several clinical and organizational barriers. In this study we investigated the physical functional status of a cohort of dialysis patients, using a multidimensional assessment.

Methods: Four hundred and forty-six individuals from 8 hemodialysis centers (176 females), mean age 67.5 ± 14.1 years, and dialysis vintage 62 ± 72.1 months, were assessed by a multidimensional battery including Short Form Health Survey (SF12), Elderly Falls Screening Test (EFST), Short Physical Performance Battery (SPPB), and Handgrip Strength Test (HST). Individuals were stratified into 3 groups (poor, moderate, and good performers) according to the SPPB score. Functional assessments were performed by staff nurses, with the support of physiotherapists and nephrologists.

Results: According to SPPB, 53.4% of dialysis patients showed a severe physical impairment. A significant difference emerged among the 3 SPPB groups for age, HST, EFST, and SF12. The main predictors of the SPPB score group were age (p = 0.0001), EFST (p = 0.028 moderate performers and p = 0.0001 poor performers), dominant HST (p = 0.04 moderate performers), and SF12 physical (p = 0.003 moderate performers and p = 0.0001 poor performers). Each age group showed physical performance comparable to a healthy general population of 10 years older.

Conclusions: Our results confirmed the severe impairment of physical function in the end stage kidney disease population. The multidimensional assessment showed that SPPB test is an effective tool to stratify the dialysis population. Moreover, EFST, HST, and SF12 may contribute to the definition of a tailored physical activity program based on patient characteristics.

Introduction: A comprehensive pathophysiological mechanism to explain the relationship between high-salt intake and hypertension remains undefined. Evidence suggests that chloride, as the accompanying anion of sodium in dietary salt, is necessary to develop hypertension. We evaluated whether reducing dietary Cl- while keeping a standard Na+ intake modified blood pressure, cardiac hypertrophy, renal function, and vascular contractility after angiotensin II (AngII) infusion.

Methods: C56BL/6J mice fed with standard Cl- diet or a low-Cl- diet (equimolar substitution of Cl- by a mixture of Na+ salts, both diets with standard Na+ content) received AngII (infusion of 1.5 mg/kg/day) or vehicle for 14 days. We measured systolic blood pressure (SBP), glomerular filtration rate (GFR), natriuretic response to acute saline load, and contractility of aortic rings from mice infused with vehicle and AngII, in standard and low-Cl- diet.

Results: The mice fed the standard diet presented increased SBP and cardiac hypertrophy after AngII infusion. In contrast, low-Cl- diet prevented the increase of SBP and cardiac hypertrophy. AngII-infused mice fed a standard diet presented hampered natriuretic response to saline load, meanwhile the low-Cl- diet preserved natriuretic response in AngII-infused mice, without change in GFR. Aortic rings from mice fed with standard diet or low-Cl- diet and infused with AngII presented a similar contractile response.

Conclusion: We conclude that the reduction in dietary Cl- as the accompanying anion of sodium in salt is protective from AngII pro-hypertensive actions due to a beneficial effect on kidney function and preserved natriuresis.

Background: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease with a prevalence of 1:400 to 1:1,000 in Caucasians. It is caused by mutations in the PKD1 gene located on chromosome 16p13.3 (in about 85% cases) as well as in the PKD2 gene on chromosome 4q13-23. In the Polish population, the disease is associated with PKD1 mutations in 84% of the ADPKD-affected families. PKD1 and PKD2 genes encode the proteins polycystin-1 (PC1) and polycystin-2 (PC2), respectively. The presence of kidney cysts is a characteristic feature in the ADPKD patients. But in the ADPKD patients, cardiovascular abnormalities, such as hypertension (HT) with higher systolic blood pressure (SBP) and diastolic blood pressure (DBP) values, higher left ventricular mass (LVM), intracranial (ICAN) and extracranial aneurysms, and cardiac valve defects, are significantly more common than in the general population.

Summary: According to the literature data, both higher LVM and vascular dysfunction already occur in children and young adults with normal renal function and without HT. Moreover, biventricular diastolic dysfunction, endothelial dysfunction, increased carotid intima-media thickness, and impaired coronary flow velocity reserve are present even in young patients with ADPKD who have normal HT and well-preserved renal function. In patients with ADPKD, hypertension has some specific features; in the youngest age group of children, the prevalence of hypertension is greater if their parents suffer from hypertension; in normotensive young ADPKD-diagnosed individuals, ambulant SBP and DBP values were significantly higher than in age- and gender-matched controls; hypertension appears at least 10 years earlier than spontaneous HT in general population. In adults, HT is often diagnosed before any substantial reduction in the GFR, and a lower nocturnal dip in BP in comparison to hypertensives in the general population. PKD1 and PKD2 gene products (PC1 and PC2 proteins) have been shown to assemble at the plasma membrane and to regulate calcium (Ca2+) entry. A defect in Ca2+ binding mediated by mutations in polycystin proteins is a hypothetical factor contributing to left ventricular mass increase. Altered intracellular Ca2+ handling contributes importantly to impaired contractility associated with heart failure. Impairment of intracellular Ca2+ homeostasis and mitochondrial function has been implicated in the development of LVH.

Key messages: It can be assumed that the cause of LVH in ADPKD patients is the natural course of this disease with developing HT and deteriorating kidney function, which may be influenced by the presence of PKD1- and PKD2-mutated gene products: PC1 and PC2 proteins.