Anemia and atrial fibrillation as independent risk factors for new-onset chronic kidney disease: the TAMA-MED Project-CKD and AF.

BACKGROUND: Various risk factors have been identified for the new onset or rapid deterioration of chronic kidney disease (CKD). However, it is thought that many risk factors that have not yet been clarified remain. METHODS: Based on the results of specific annual health checkups at Tama City (n = 18 383) in 2017 and 2018, we analyzed the factors that cause new-onset CKD and the risk factors that rapidly worsen renal function. For new-onset CKD, proteinuria and estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 were examined separately. Rapid deterioration of renal function was defined as an eGFR ≥25% less than the previous year. RESULTS: Multivariate analysis showed that in addition to age and impaired glucose tolerance, anemia and atrial fibrillation (AF) were risk factors for the new appearance of proteinuria. Risk factors for a decrease in eGFR to <60 mL/min/1.73 m2 were age and hyperuricemia. Age, systolic hypertension, urinary protein and urinary occult blood, high triglycerides and anemia were significant risk factors for the rapid deterioration of renal function in patients with CKD Stage ≥3. CONCLUSIONS: From the results of specific annual health checkups at Tama City, AF, anemia and hyperuricemia were identified as risk factors for new-onset CKD over a short period of 1 year. Anemia was also a factor for the rapid deterioration of kidney function in subjects with renal dysfunction.

Effective improvement of minimal change nephrotic syndrome with uncontrollable high low-density lipoprotein cholesterol level using evolocumab accompanied by the development of acute pancreatitis.

Nephrotic syndrome is sometimes refractory; however, it is rarely accompanied by acute pancreatitis. A 47-year-old Japanese woman complaining of limb edema was diagnosed with nephrotic syndrome. Blood and urine examinations suggested minimal change nephrotic syndrome (MCNS), and pulse intravenous methylprednisolone was administered, followed by oral prednisolone. Although proteinuria improved, the patient's condition remained unchanged, and diuresis was insufficient. As in patients with other nephrotic syndromes, this patient showed significant dyslipidemia. Atorvastatin was started for remarkable dyslipidemia since her admission, but her low-density lipoprotein cholesterol (LDL-C) level did not improve significantly. During the clinical course, she developed acute pancreatitis, and large-volume fluid replacement was performed. Although diuretic levels were increased in response to the increased fluid volume, diuresis was not enough, and lung edema developed. Extracorporeal ultrafiltration was started to ameliorate the lung edema. With the onset of pancreatitis, oral intake, including atorvastatin, was discontinued, and prednisolone was administered intravenously. To treat the high-LDL cholesterolemia, 140 mg of evolocumab was injected subcutaneously. Nausea slightly decreased on the following day, and the administration of 150 mg cyclosporine was initiated. LDL-C levels, proteinuria, and renal function promptly ameliorated. The results of a renal biopsy suggested MCNS. On the 44th day of hospitalization, she had complete remission. Evolocumab is potentially effective for severe nephrotic syndrome with uncontrollable dyslipidemia.

Identification of a physiological phosphorylation site of the herpes simplex virus 1-encoded protein kinase Us3 which regulates its optimal catalytic activity in vitro and influences its function in infected cells.

Us3 is a serine/threonine protein kinase encoded by herpes simplex virus 1 (HSV-1). Here, we report the identification of a physiological Us3 phosphorylation site on serine at position 147 (Ser-147) which regulates its protein kinase activity in vitro. Moreover, mutation of this site influences Us3 function, including correct localization of the enzyme and induction of the usual morphological changes in HSV-1-infected cells. These conclusions are based on the following observations: (i) in in vitro kinase assays, a domain of Us3 containing Ser-147 was specifically phosphorylated by Us3 and protein kinase A, while a mutant domain in which Ser-147 was replaced with alanine was not; (ii) in vitro, alanine replacement of Ser-147 (S147A) in Us3 resulted in significant impairment of the kinase activity of the purified molecule expressed in a baculovirus system; (iii) phosphorylation of Ser-147 in Us3 tagged with the monomeric fluorescent protein (FP) VenusA206K (VenusA206K-Us3) from Vero cells infected with a recombinant HSV-1 encoding VenusA206K-Us3 was specifically detected using an antibody that recognizes phosphorylated serine or threonine residues with arginine at the -3 and -2 positions; and (iv) the S147A mutation influenced some but not all Us3 functions, including the ability of the protein to localize itself properly and to induce wild-type cytopathic effects in infected cells. Our results suggest that some of the regulatory activities of Us3 in infected cells are controlled by phosphorylation at Ser-147.

Identification of proteins directly phosphorylated by UL13 protein kinase from herpes simplex virus 1.

Herpes simplex virus 1 (HSV-1) UL13 is a viral protein kinase that regulates optimal viral replication in cell cultures. Identification of substrates of protein kinases is a crucial step to elucidate the mechanism by which they function. Using our developed system to analyze the specific protein kinase activity of UL13, we have shown that UL13 protein kinase directly phosphorylates the viral proteins ICP22 and UL49 previously reported to be putative substrates. We also identified UL41 as a previously unreported and novel substrate of UL13. These data will serve as a basis to clarify the mechanism by which UL13 influences viral replication.

Epstein-Barr virus protein kinase BGLF4 interacts with viral transactivator BZLF1 and regulates its transactivation activity.

BGLF4 is a serine/threonine protein kinase encoded by Epstein-Barr virus. One of the physiological substrates of BGLF4 is viral transactivator BZLF1. In the present study, it was demonstrated that alanine substitution of the serine residue at position 209 (S209A) in BZLF1 eliminated phosphorylation of the protein by BGLF4 in vitro. The S209A mutation in BZLF1, as well as a K102I mutation in BGLF4, which inactivated catalytic activity of the viral kinase, also inhibited formation of a stable BGLF4-BZLF1 complex and downregulation of BZLF1 autotransactivation activity mediated by BGLF4. These results indicate that formation of a stable complex of BGLF4-BZLF1 enables downregulation of BZLF1 autoregulation activity and it appears that BGLF4 phosphorylation of BZLF1 may be involved in these processes.

Epstein-Barr virus protein kinase BGLF4 is a virion tegument protein that dissociates from virions in a phosphorylation-dependent process and phosphorylates the viral immediate-early protein BZLF1.

Epstein-Barr virus (EBV) BGLF4 is a viral protein kinase that is expressed in the lytic phase of infection and is packaged in virions. We report here that BGLF4 is a tegument protein that dissociates from the virion in a phosphorylation-dependent process. We also present evidence that BGLF4 interacts with and phosphorylates BZLF1, a key viral regulator of lytic infection. These conclusions are based on the following observations. (i) In in vitro tegument release assays, a significant fraction of BGLF4 was released from virions in the presence of physiological NaCl concentrations. (ii) Addition of physiological concentrations of ATP and MgCl(2) to virions enhanced BGLF4 release, but phosphatase treatment of virions significantly reduced BGLF4 release. (iii) A recombinant protein containing a domain of BZLF1 was specifically phosphorylated by purified recombinant BGLF4 in vitro, and BGLF4 altered BZLF1 posttranslational modification in vivo. (iv) BZLF1 was specifically coimmunoprecipitated with BGLF4 in 12-O-tetradecanoylphorbol-13-acetate-treated B95-8 cells and in COS-1 cells transiently expressing both of these viral proteins. (v) BGLF4 and BZLF1 were colocalized in intranuclear globular structures, resembling the viral replication compartment, in Akata cells treated with anti-human immunoglobulin G. Our results suggest that BGLF4 functions not only in lytically infected cells by phosphorylating viral and cellular targets but also immediately after viral penetration like other herpesvirus tegument proteins.