Nicotinamide Attenuates the Progression of Renal Failure in a Mouse Model of Adenine-Induced Chronic Kidney Disease.

Nicotinamide adenine dinucleotide (NAD+) supplies energy for deoxidation and anti-inflammatory reactions fostering the production of adenosine triphosphate (ATP). The kidney is an essential regulator of body fluids through the excretion of numerous metabolites. Chronic kidney disease (CKD) leads to the accumulation of uremic toxins, which induces chronic inflammation. In this study, the role of NAD+ in kidney disease was investigated through the supplementation of nicotinamide (Nam), a precursor of NAD+, to an adenine-induced CKD mouse model. Nam supplementation reduced kidney inflammation and fibrosis and, therefore, prevented the progression of kidney disease. Notably, Nam supplementation also attenuated the accumulation of glycolysis and Krebs cycle metabolites that occurs in renal failure. These effects were due to increased NAD+ supply, which accelerated NAD+-consuming metabolic pathways. Our study suggests that Nam administration may be a novel therapeutic approach for CKD prevention.

Glomerular Injury Is Exacerbated in Lupus-Prone MRL/lpr Mice Treated with a Protease-Activated Receptor 2 Antagonist.

Systemic lupus erythematosus (SLE) is characterized by the production of autoantibodies, which causes multi-organ injury such as lupus nephritis. SLE is associated with hypercoagulability. Activated coagulation factors such as tissue factor and VIIa complex and factor Xa activate protease-activated receptor 2 (PAR2). PAR2 promotes cytokine production through mitogen-activated protein kinase or nuclear factor kappa B signaling, and previous reports demonstrated that inhibition of PAR2 alleviated kidney injuries such as diabetic kidney disease and renal fibrosis in animal models. However, the involvement of PAR2 in the pathogenesis of SLE remains unclear. We therefore administered a selective PAR2 peptide antagonist, FSLLRY-NH2, to SLE-prone 4-month-old MRL-Faslpr mice for 4 weeks. Treatment with FSLLRY-NH2 caused the significant increases in the glomerular mesangial proliferation, glomerular deposition of both immunoglobulin G and complement factor C3d, and glomerular infiltration of Mac2-positive macrophages and CD3-positive T cells, compared with MRL-Faslpr mice treated with saline. In addition, the treatment with the PAR2 antagonist increased renal expression levels of tumor necrosis factor-α (Tnfa) and monocyte chemoattractant protein 1 (Mcp1) mRNA. Collectively, these results suggest that inhibition of PAR2 may increase the severity of inflammation in lupus nephritis; namely, opposite to previous observations, PAR2 has anti-inflammatory properties. We propose that activation of PAR2 could serve as a potential therapeutic option for patients with SLE.

A Catastrophic Case of Idiopathic Cholesterol Crystal Embolism with Multiple Lethal Complications: A Labyrinth Underneath the Diagnosis of Skin Ulcers in Chronic Kidney Disease Patients.

A 66-year-old man was admitted to our hospital because of multiple refractory skin ulcers. Based on his severe systemic arterial calcification and severe calcium-phosphate imbalance due to severe kidney dysfunction, we initially considered calciphylaxis. However, a skin biopsy provided a diagnosis of cholesterol crystal embolization. Although we initiated hemodialysis, steroid treatment, and low-density lipoprotein-cholesterol apheresis, he died of multiple intestinal perforation. An autopsy showed cholesterol crystals occluding multiple organ arterioles. This case suggests that skin ulcers in patients with chronic kidney disease may be an important diagnostic hallmark and may be associated with several serious diseases.

Kartagener's syndrome and rheumatoid arthritis.

We herein present the case of a 47-year-old woman with rheumatoid arthritis (RA) complicated by Kartagener's syndrome (KS). Although her RA disease activity score (DAS28-CRP) decreased following the administration of periodontitis treatment and etanercept, she did not achieve symptom relief or DAS28-CRP remission. After undergoing surgery for chronic sinusitis, her articular symptoms improved and the DAS28-CRP declined to the level of remission. Patients with KS may develop respiratory infections due to an impaired defense mechanism against microbes in the airway. Therefore, in patients with RA complicated by KS, comprehensive management of infection, including surgical therapy for sinusitis, is needed to reduce the RA disease activity.