High-Density Lipoproteins and Acute Kidney Injury

Exploring therapeutic mechanisms of Chuan Huang Fang-II in the treatment of acute kidney injury on chronic kidney disease patients from the perspective of lipidomics

OBJECTIVE

This study aims to assess the clinical efficacy and safety of CHF-II in combination with RG for treating AKI on CKD (A on C), and to explore potential therapeutic mechanisms through lipidomics analysis.

METHODS

98 patients were enrolled and randomly assigned to the RG or RG + CHF groups. Both groups received RG therapy, with RG + CHF group additionally receiving CHF-II treatment over a duration of two weeks. Evaluation endpoints included changes in renal function, blood lipid profiles, urinary AKI biomarkers, and TCM symptoms before and after treatment. Serum samples were collected for lipid metabolite analysis.

RESULTS

The total clinical effective rate in RG + CHF group was 73.5%, and that of RG group was 40.8%. TCM syndrome scores in RG + CHF group showed a more pronounced decrease (p < 0.05). Scr, BUN, and UA levels decreased while eGFR levels increased in both groups (p < 0.05), with a greater magnitude of change observed in the RG + CHF group. Urinary AKI biomarkers decreased more in RG + CHF group (p < 0.05). No serious adverse events occurred during the trial. 58 different lipid metabolites and 48 lipid biomarkers were identified. According to the KEGG database, the possible metabolic pathways involved triglyceride metabolic pathway and fat digestion and absorption metabolic pathways.

CONCLUSION

CHF-II effectively alleviated kidney injury and improved TCM syndrome scores in patients with A on C. Lipid differential metabolites could serve as diagnostic indicators for AKI in patients with CKD. The possible metabolic pathways might be implicated in therapeutic action of CHF-II in the prevention and treatment of patients with A on C.

The association of dyslipidemia with kidney stone: result from the NHANES 2007-2020

OBJECTIVE

To examine the association between dyslipidemia and kidney stone disease (KSD).

METHODS

A cross-sectional study data from 2007 to 2020 National Health and Nutrition Examination Survey (NHANES) were analyzed. Multivariate logistic regression was conducted with serum lipid levels as the exposure and presence of KSD as the outcome, and included adjustment for confounders and subgroup analysis.

RESULTS

A total of 38,617 participants were enrolled and classified into two groups according to whether they ever had (n = 3689) or did not have (n = 34,928) KSD. After multivariate logistic regression models, compared to quartile 1 (Q1) of lipid profile, the participants in Q3 (OR 0.8380; 95 CI 0.7380, 0.9515, P < 0.01) and Q4 (OR 0.7373; 95 CI 0.6377, 0.8525, P < 0.01) of high-density lipoprotein cholesterol (HDL) had a significantly lower risk of KSD in adjusted model 3. Results remained stable after stratified by age, gender, and body mass index (BMI) in subgroup analysis. No association was observed between low-density lipoprotein cholesterol (LDL), total cholesterol (TC) and triglycerides (TG) levels, and KSD.

CONCLUSIONS

Low HDL was associated with a higher risk of kidney stones in the USA adult population.

Comparison of in-gel and in-solution proteolysis in the proteome profiling of organ perfusion solutions

PURPOSE

The organ perfusion solution (perfusate), collected at clinically and temporally significant stages of the organ preservation and transplantation process, provides a valuable insight into the biological status of an organ over time and prior to reperfusion (transplantation) in the recipient. The objective of this study was to assess two bottom-up proteomics workflows for the extraction of tryptic peptides from the perfusate.

EXPERIMENTAL DESIGN

Two different kinds of perfusate samples from kidney and liver trials were profiled using liquid chromatography-mass spectrometry (LC-MS/MS). The preparation of clean peptide mixtures for downstream analysis was performed considering different aspects of sample preparation; protein estimation, enrichment, in-gel and urea-based in-solution digestion.

RESULTS

In-solution digestion of perfusate allowed identification of the highest number of peptides and proteins with greater sequence coverage and higher confidence data in kidney and liver perfusate. Key pathways identified by gene ontology analysis included complement, coagulation and antioxidant pathways, and a number of biomarkers previously linked to ischemia-reperfusion injury were also observed in perfusate.

CONCLUSIONS

This study showed that in-solution digestion is a more efficient method for LC-MS/MS analysis of kidney and liver organ perfusion solutions. This method is also quicker and easier than in-gel digestion, allowing for greater sample throughput, with fewer opportunities for experimental error or peptide loss.

The Association of the Levels of High-Density Lipoprotein and Apolipoprotein A1 with SARS-CoV-2 Infection and COVID-19 Severity: An Analysis of the N3C Database

This study analyzed data from the National COVID Cohort Collaborative (N3C) database to investigate whether high-density lipoprotein (HDL) and its major protein component, apolipoprotein A1 (apoA1), are associated with severe COVID-19 sequelae, specifically acute kidney injury (AKI) and severe COVID-19 disease as defined by the infection resulting in hospitalization, extracorporeal membrane oxygenation (ECMO), invasive ventilation, or death. Our study included a total of 1,415,302 subjects with HDL values and 3589 subjects with apoA1 values. Higher levels of both HDL and apoA1 were associated with a lower incidence of infection as well as a lower incidence of severe disease. Higher HDL levels were also associated with a lower incidence of developing AKI. Most comorbidities were negatively correlated with SARS-CoV-2 infection, presumably due to the behavioral changes that occurred as a result of the precautions taken by individuals with underlying comorbidities. The presence of comorbidities, however, was associated with developing severe COVID-19 disease and AKI. African American and Hispanic populations experienced worse outcomes, including a higher incidence of infection and the development of severe disease, as well as AKI. Smoking and being male were associated with a lower incidence of infection, while they were risk factors for the development of severe disease and AKI. The results on cholesterol and diabetes drugs warrant further research, given that the database included multiple drugs in each category impeding for analysis of specific medications. Despite the current limitations in the N3C data, this study is the first to investigate the roles of HDL and apoA1 on the outcomes of COVID-19 using the US population data.

Molecular and cellular mechanisms involved in tissue-specific metabolic modulation by SARS-CoV-2

Coronavirus disease 2019 (COVID-19) is triggered by the SARS-CoV-2, which is able to infect and cause dysfunction not only in lungs, but also in multiple organs, including central nervous system, skeletal muscle, kidneys, heart, liver, and intestine. Several metabolic disturbances are associated with cell damage or tissue injury, but the mechanisms involved are not yet fully elucidated. Some potential mechanisms involved in the COVID-19-induced tissue dysfunction are proposed, such as: (a) High expression and levels of proinflammatory cytokines, including TNF-α IL-6, IL-1β, INF-α and INF-β, increasing the systemic and tissue inflammatory state; (b) Induction of oxidative stress due to redox imbalance, resulting in cell injury or death induced by elevated production of reactive oxygen species; and (c) Deregulation of the renin-angiotensin-aldosterone system, exacerbating the inflammatory and oxidative stress responses. In this review, we discuss the main metabolic disturbances observed in different target tissues of SARS-CoV-2 and the potential mechanisms involved in these changes associated with the tissue dysfunction.

High-Density Lipoproteins in Kidney Disease

Decades of epidemiological studies have established the strong inverse relationship between high-density lipoprotein (HDL)-cholesterol concentration and cardiovascular disease. Recent evidence suggests that HDL particle functions, including anti-inflammatory and antioxidant functions, and cholesterol efflux capacity may be more strongly associated with cardiovascular disease protection than HDL cholesterol concentration. These HDL functions are also relevant in non-cardiovascular diseases, including acute and chronic kidney disease. This review examines our current understanding of the kidneys’ role in HDL metabolism and homeostasis, and the effect of kidney disease on HDL composition and functionality. Additionally, the roles of HDL particles, proteins, and small RNA cargo on kidney cell function and on the development and progression of both acute and chronic kidney disease are examined. The effect of HDL protein modification by reactive dicarbonyls, including malondialdehyde and isolevuglandin, which form adducts with apolipoprotein A-I and impair proper HDL function in kidney disease, is also explored. Finally, the potential to develop targeted therapies that increase HDL concentration or functionality to improve acute or chronic kidney disease outcomes is discussed.

Multifaced Roles of HDL in Sepsis and SARS-CoV-2 Infection: Renal Implications

High-density lipoproteins (HDLs) are a class of blood particles, principally involved in mediating reverse cholesterol transport from peripheral tissue to liver. Omics approaches have identified crucial mediators in the HDL proteomic and lipidomic profile, which are involved in distinct pleiotropic functions. Besides their role as cholesterol transporter, HDLs display anti-inflammatory, anti-apoptotic, anti-thrombotic, and anti-infection properties. Experimental and clinical studies have unveiled significant changes in both HDL serum amount and composition that lead to dysregulated host immune response and endothelial dysfunction in the course of sepsis. Most SARS-Coronavirus-2-infected patients admitted to the intensive care unit showed common features of sepsis disease, such as the overwhelmed systemic inflammatory response and the alterations in serum lipid profile. Despite relevant advances, episodes of mild to moderate acute kidney injury (AKI), occurring during systemic inflammatory diseases, are associated with long-term complications, and high risk of mortality. The multi-faceted relationship of kidney dysfunction with dyslipidemia and inflammation encourages to deepen the clarification of the mechanisms connecting these elements. This review analyzes the multifaced roles of HDL in inflammatory diseases, the renal involvement in lipid metabolism, and the novel potential HDL-based therapies.

Perioperative high density lipoproteins, oxidative stress, and kidney injury after cardiac surgery

Oxidative stress promotes acute kidney injury (AKI). Higher HDL cholesterol concentrations are associated with less AKI. To test the hypothesis that HDL antioxidant activity is associated with AKI after cardiac surgery, we quantified HDL particle (HDL-P) size and number, paraoxonase-1 (PON-1) activity, and isofuran concentrations in 75 patients who developed AKI and 75 matched control patients. Higher preoperative HDL-P was associated with less AKI (OR: 0.80; 95% CI, 0.71-0.91; P = 0.001), higher PON-1 activity ( P < 0.001), and lower plasma concentrations of isofurans immediately after surgery (P = 0.02). Similarly, higher preoperative small HDL-P was associated with less AKI, higher PON-1 activity, and lower isofuran concentrations. Higher intraoperative particle losses were associated with less AKI (OR: 0.79; 95% CI 0.67-0.93; P = 0.005), and with decreased postoperative isofuran concentrations (P = 0.04) . Additionally, higher preoperative small HDL-P and increased intraoperative small particle loss were associated with improved long-term renal function (P = 0.003, 0.01, respectively). In conclusion, a higher preoperative concentration of HDL-P, particularly small particles, is associated with lower oxidative damage and less AKI. Perioperative changes in HDL-P concentrations are also associated with AKI. Small HDL-P may represent a novel modifiable risk factor for AKI.