[Roles of coagulation pathway and factor Xa in chronic kidney disease (CKD)]

The Potential Role of Coagulation Factor Xa in the Pathophysiology of COVID-19: A Role for Anticoagulants as Multimodal Therapeutic Agents

SARS-CoV-2 infection (COVID-19) results in local and systemic activation of inflammation and coagulation. In this review article, we will discuss the potential role of coagulation factor Xa (FXa) in the pathophysiology of COVID-19. FXa, a serine protease, has been shown to play a role in the cleavage of SARS-CoV-1 spike protein (SP), with the inhibition of FXa resulting in the inhibition of viral infectivity. FX is known to be primarily produced in the liver, but it is also expressed by multiple cells types, including alveolar epithelium, cardiac myocytes, and macrophages. Considering that patients with preexisting conditions, including cardiopulmonary disease, are at an increased risk of severe COVID-19, we discuss the potential role of increased levels of FX in these patients, resulting in a potential increased propensity to have a higher infectious rate and viral load, increased activation of coagulation and inflammation, and development of fibrosis. With these observations in mind, we postulate as to the potential therapeutic role of FXa inhibitors as a prophylactic and therapeutic treatment for high-risk patients with COVID-19.

Protective Efficacy of the Ingestion of Mandarin Orange Containing β-Cryptoxanthin on Lipopolysaccharide-induced Acute Nephritis

β-cryptoxanthin is a common carotenoid pigment found in fruit, especially in Satsuma mandarins and in persimmons. After ingestion, β-cryptoxanthin is distributed to and accumulates in organs, such as the liver, lung, and kidney. Recent studies have reported that because of its antioxidant defense, β-cryptoxanthin performs several important functions in the preservation of human health and in the prevention of several diseases, including cancer and osteoporosis. The present study aims to determine whether β-cryptoxanthin has a protective effect on renal glomeruli during acute nephritis. To develop our acute nephritis mouse model, we induced kidney inflammation in mice using lipopolysaccharide. To analyze pathological changes in the renal glomeruli of these mice, tissue sections of the kidney were analyzed by hematoxylin-eosin and periodic acid-Schiff staining. In mice with acute nephritis, we observed a thickening of the basal membrane in the renal glomeruli. By ultrastructural analysis, abnormalities in the foot cells were also identified. In the β-cryptoxanthin-ingested mice, these pathological changes were decreased. Migration of urinal proteins occurred in mice with acute nephritis, but this was decreased in β-cryptoxanthin-ingested mice, such that it correlated with the blood concentration of β-cryptoxanthin. Furthermore, in β-cryptoxanthin-ingested mice, both the accumulation and activation of inflammatory cells were decreased in the renal glomeruli. These results suggest that β-cryptoxanthin ingestion may produce great improvement in acute nephritis. These findings provide new insights into β-cryptoxanthin and its protective effect, and provide a new target for pharmacological therapy in human disease.

Plasma metabolomic profiles in different stages of CKD

BACKGROUND AND OBJECTIVES

CKD is a common public health problem. Identifying biomarkers adds prognostic/diagnostic value by contributing to an understanding of CKD at the molecular level and possibly defining new drug targets. Metabolomics provides a snapshot of biochemical events at a particular time in the progression of CKD. This cross-sectional metabolomics study ascertained whether plasma metabolite profiles are significantly different in CKD stages 2, 3, and 4.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

An analysis of plasma metabolites, using gas and liquid chromatography coupled to mass spectrometry, was conducted on 30 nondiabetic men ages 40-52 years, with 10 participants each in CKD stages 2, 3, and 4 based on their estimated GFR (calculated by the Modified Diet in Renal Disease formula). Participants were recruited in late 2008, and plasma samples were tested at Metabolon Inc and analyzed in 2012.

RESULTS

Comparison of stage 3/stage 2 identified 62 metabolites that differed (P ≤ 0.05), with 39 higher and 23 lower in stage 3 compared with stage 2; comparisons of stage 4/stage 2 identified 111 metabolites, with 66 higher and 45 lower; and comparisons of stage 4/stage 3 identified 11 metabolites, with 7 higher and 4 lower. Major differences in metabolite profiles with increasing stage of CKD were observed, including altered arginine metabolism, elevated coagulation/inflammation, impaired carboxylate anion transport, and decreased adrenal steroid hormone production.

CONCLUSIONS

Global metabolite profiling of plasma uncovered potential biomarkers of stages of CKD. Moreover, these biomarkers provide insight into possible pathophysiologic processes that may contribute to progression of CKD.